Internal Server Error after Upgrade to Nextcloud 15

Hi,
after automatic Upgrade to Nextcloud 15 in NextcloudPi i cant acces my Nextcloud anymore.
However, the Management interface on port 4443 still works.

Following Error is shown:

Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

Logs:

Nextcloud configuration

{
    "system": {
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": {
            "0": "localhost",
            "7": "nextcloudpi",
            "8": "nextcloudpi.lan",
            "1": "192.168.2.11",
            "4": "cloud.mydomain.de",
            "11": "80.135.54.119"
        },
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "15.0.2.0",
        "overwrite.cli.url": "https:\/\/cloud.mydomain\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0,
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "overwriteprotocol": "https",
        "htaccess.RewriteBase": "",
        "loglevel": "2",
        "log_type": "file",
        "maintenance": false,
        "mail_smtpauth": 1,
        "mail_smtpsecure": "ssl",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "data-fingerprint": "06c56308833bf61c07dc2dccaf64b86e",
        "theme": ""
    }
}

HTTPd logs

[Mon Jan 21 14:27:15.081058 2019] [authz_host:error] [pid 911:tid 1690526768] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:15.081892 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /img/green-circle.svg failed, reason: unable to get the remote host name, referer: https://192.168.2.11:4443/css/ncp.css
[Mon Jan 21 14:27:15.086520 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to / failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:15.270760 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to / failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:15.271168 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /index.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:15.455881 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /index.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:18.475510 2019] [authz_host:error] [pid 911:tid 1682129968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /js/minified.js failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:18.476779 2019] [authz_host:error] [pid 911:tid 1715717168] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /css/ncp.css failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:18.476778 2019] [authz_host:error] [pid 911:tid 1690526768] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /js/ncp.js failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:18.477540 2019] [authz_host:error] [pid 911:tid 1698923568] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /img/ncp-logo.svg failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:18.478268 2019] [authz_host:error] [pid 911:tid 1724113968] [client 192.168.2.201:51092] AH01753: access check of 'localhost' to /img/loading-small.gif failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:19.115037 2019] [authz_host:error] [pid 910:tid 1724113968] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-output.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:19.115042 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:27:27.098374 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:31:30.185650 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:31:49.331840 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:31:51.442974 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:31:51.445192 2019] [authz_host:error] [pid 910:tid 1715717168] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /img/green-circle.svg failed, reason: unable to get the remote host name, referer: https://192.168.2.11:4443/css/ncp.css
[Mon Jan 21 14:34:49.552177 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name
[Mon Jan 21 14:34:49.899695 2019] [authz_host:error] [pid 910:tid 1707320368] [client 192.168.2.201:51252] AH01753: access check of 'localhost' to /ncp-launcher.php failed, reason: unable to get the remote host name

Database logs

2019-01-21 14:18:59 1988698112 [Note] InnoDB: innodb_empty_free_list_algorithm has been changed to legacy because of small buffer pool size. In order to use backoff, increase buffer pool at least up to 20MB.

2019-01-21 14:18:59 1988698112 [Note] InnoDB: Using mutexes to ref count buffer pool pages
2019-01-21 14:18:59 1988698112 [Note] InnoDB: The InnoDB memory heap is disabled
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2019-01-21 14:18:59 1988698112 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Compressed tables use zlib 1.2.8
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Using Linux native AIO
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Using generic crc32 instructions
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Completed initialization of buffer pool
2019-01-21 14:18:59 1988698112 [Note] InnoDB: Highest supported file format is Barracuda.
2019-01-21 14:19:00 1988698112 [Note] InnoDB: 128 rollback segment(s) are active.
2019-01-21 14:19:00 1988698112 [Note] InnoDB: Waiting for purge to start
2019-01-21 14:19:00 1988698112 [Note] InnoDB:  Percona XtraDB (http://www.percona.com) 5.6.41-84.1 started; log sequence number 157693887
2019-01-21 14:19:00 1409282880 [Note] InnoDB: Dumping buffer pool(s) not yet started
2019-01-21 14:19:00 1988698112 [Note] Plugin 'FEEDBACK' is disabled.
2019-01-21 14:19:00 1988698112 [Note] Server socket created on IP: '127.0.0.1'.
2019-01-21 14:19:00 1988698112 [Note] /usr/sbin/mysqld: ready for connections.
Version: '10.1.37-MariaDB-0+deb9u1'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  Raspbian 9.0

Hi,
I have the same problem and it seems all my users files are missing from data directory.
Maybe its less trouble to start over and restore data from backup.

I have a recent backup, so that woldnt be a problem. But after restoring the backup, i will be on 14 again, right?
Or is there an NCP image with NC15 in it?

Because i already started from scratch two days ago for the same reason and after the upgrade last night, again internal server error.

Have you tried this image https://ownyourbits.com/downloads/NextCloudPi_RPi_01-13-19/ ?
I belive it’s NC15 but havent had time to try yet.

I Used exactly the image you mentioned.
But unfortunately its NC 14.

If i try to recover a backup now, will i stay on NC15?

I used that image (link above from @jolinds) and it installed NC 15.0.1 and NCP v1.2
So @damole1984 : suggest you try with latest image, it updates fine to NC15.0.2 and NCPv1.4.1 (at present).

Or if you have restored from backup: from terminal first run ncp-update or from ncp-web:4443 select nc-update-ncp to update ncp to latest and then nc-update-nc to update to 15.0.2

So, new update. I recovered the last working backup and went back to 14.0.4.2 with it. Everything worked fine.
Then i started ncp-update via ssh as @OliverV suggested.
NCP Update to 1.4.4 went well. Then i started nc-update-nextcloud from the management site.
After the upgrade, again “internal server error”.

Here is the output of the nc-update-nextcloud window:

[ nc-update-nextcloud ]
Current Nextcloud version 14.0.4.2
Available Nextcloud version 15.0.2
Download Nextcloud 15.0.2…
Back up current instance…
check free space…
Maintenance mode enabled
backup database…
backup files…
backup /var/www//nextcloud-bkp_20190122_1548185256.tar.gz generated
Maintenance mode disabled
Install Nextcloud 15.0.2…
Restore apps…
* admin_notifications
* calendar
* contacts
* news
* nextcloudpi
* notes
* previewgenerator
* tasks
* user_external
Fix permissions…
Upgrade…
PHP Warning: fileperms(): stat failed for /var/www/nextcloud/data/nextcloud.log in /var/www/nextcloud/lib/private/Log/File.php on line 140
{“reqId”:“MFg6BOvgJ44jFQVcDxjh”,“level”:3,“time”:“2019-01-22T19:33:00+00:00”,“remoteAddr”:“”,“user”:“–”,“app”:“PHP”,“method”:“”,“url”:“–”,“message”:“fileperms(): stat failed for /var/www/nextcloud/data/nextcloud.log at /var/www/nextcloud/lib/private/Log/File.php#140”,“userAgent”:“–”,“version”:“14.0.4.2”}
{“reqId”:“MFg6BOvgJ44jFQVcDxjh”,“level”:2,“time”:“2019-01-22T19:33:00+00:00”,“remoteAddr”:“”,“user”:“–”,“app”:“no app in context”,“method”:“”,“url”:“–”,“message”:“Temporary directory /var/www/nextcloud/data/tmp is not present or writable”,“userAgent”:“–”,“version”:“14.0.4.2”}
Nextcloud or one of the apps require upgrade - only a limited number of commands are available
You may use your browser or the occ upgrade command to do the upgrade
Set log level to debug
Turned on maintenance mode
Updating database schema
Updated database
Disabled incompatible app: admin_notifications
Updating <accessibility> …
Updated <accessibility> to 1.1.0
Updating <federatedfilesharing> …
Updated <federatedfilesharing> to 1.5.0
Updating <files_pdfviewer> …
Updated <files_pdfviewer> to 1.4.0
Updating <files_texteditor> …
Updated <files_texteditor> to 2.7.0
Updating <files_videoplayer> …
Updated <files_videoplayer> to 1.4.0
Updating <gallery> …
Updated <gallery> to 18.2.0
Updating <password_policy> …
Updated <password_policy> to 1.5.0
Updating <provisioning_api> …
Updated <provisioning_api> to 1.5.0
Updating <serverinfo> …
Updated <serverinfo> to 1.5.0
Updating <survey_client> …
Updated <survey_client> to 1.3.0
Updating <twofactor_backupcodes> …
Updated <twofactor_backupcodes> to 1.4.1
Updating <updatenotification> …
Updated <updatenotification> to 1.5.0
Updating <federation> …
Updated <federation> to 1.5.0
Updating <lookup_server_connector> …
Updated <lookup_server_connector> to 1.3.0
Updating <oauth2> …
Updated <oauth2> to 1.3.0
Updating <files> …
Updated <files> to 1.10.0
Updating <activity> …
Updated <activity> to 2.8.2
Updating <cloud_federation_api> …
Updated <cloud_federation_api> to 0.1.0
Updating <dav> …
Fix broken values of calendar objects

Starting …
0/0 [>---------------------------] 0%
Updated <dav> to 1.8.1
Updating <files_external> …
Updated <files_external> to 1.6.0
Updating <files_sharing> …
Updated <files_sharing> to 1.7.0
Updating <files_trashbin> …
Updated <files_trashbin> to 1.5.0
Updating <files_versions> …
Updated <files_versions> to 1.8.0
Updating <sharebymail> …
Updated <sharebymail> to 1.5.0
Updating <workflowengine> …
Updated <workflowengine> to 1.5.0
Updating <comments> …
Updated <comments> to 1.5.0
Updating <firstrunwizard> …
Updated <firstrunwizard> to 2.4.0
Updating <nextcloud_announcements> …
Updated <nextcloud_announcements> to 1.4.0
Updating <notifications> …
Updated <notifications> to 2.3.0
Updating <systemtags> …
Updated <systemtags> to 1.5.0
Updating <theming> …
Updated <theming> to 1.6.0
Checking for update of app accessibility in appstore
stat: cannot stat ‘/var/www/nextcloud/data/appdata_oc9p06rr6da2/appstore/apps.json’: No such file or directory
Checked for update of app “accessibility” in appstore
Checking for update of app activity in appstore
Checked for update of app “activity” in appstore
Checking for update of app calendar in appstore
Checked for update of app “calendar” in appstore
Checking for update of app cloud_federation_api in appstore
Checked for update of app “cloud_federation_api” in appstore
Checking for update of app comments in appstore
Checked for update of app “comments” in appstore
Checking for update of app contacts in appstore
Checked for update of app “contacts” in appstore
Checking for update of app dav in appstore
Checked for update of app “dav” in appstore
Checking for update of app federatedfilesharing in appstore
Checked for update of app “federatedfilesharing” in appstore
Checking for update of app federation in appstore
Checked for update of app “federation” in appstore
Checking for update of app files in appstore
Checked for update of app “files” in appstore
Checking for update of app files_external in appstore
Checked for update of app “files_external” in appstore
Checking for update of app files_pdfviewer in appstore
Checked for update of app “files_pdfviewer” in appstore
Checking for update of app files_sharing in appstore
Checked for update of app “files_sharing” in appstore
Checking for update of app files_texteditor in appstore
Checked for update of app “files_texteditor” in appstore

Checking for update of app files_trashbin in appstore
Checked for update of app “files_trashbin” in appstore
Checking for update of app files_versions in appstore
Checked for update of app “files_versions” in appstore
Checking for update of app files_videoplayer in appstore
Checked for update of app “files_videoplayer” in appstore
Checking for update of app firstrunwizard in appstore
Checked for update of app “firstrunwizard” in appstore
Checking for update of app gallery in appstore
Checked for update of app “gallery” in appstore
Checking for update of app logreader in appstore
Checked for update of app “logreader” in appstore
Checking for update of app lookup_server_connector in appstore
Checked for update of app “lookup_server_connector” in appstore
Checking for update of app news in appstore
Checked for update of app “news” in appstore
Checking for update of app nextcloud_announcements in appstore
Checked for update of app “nextcloud_announcements” in appstore
Checking for update of app nextcloudpi in appstore
Checked for update of app “nextcloudpi” in appstore
Checking for update of app notes in appstore
Checked for update of app “notes” in appstore
Checking for update of app notifications in appstore
Checked for update of app “notifications” in appstore
Checking for update of app oauth2 in appstore
Checked for update of app “oauth2” in appstore
Checking for update of app password_policy in appstore
Checked for update of app “password_policy” in appstore
Checking for update of app previewgenerator in appstore
Checked for update of app “previewgenerator” in appstore
Checking for update of app provisioning_api in appstore
Checked for update of app “provisioning_api” in appstore
Checking for update of app serverinfo in appstore
Checked for update of app “serverinfo” in appstore
Checking for update of app sharebymail in appstore
Checked for update of app “sharebymail” in appstore
Checking for update of app support in appstore
Checked for update of app “support” in appstore
Checking for update of app survey_client in appstore
Checked for update of app “survey_client” in appstore
Checking for update of app systemtags in appstore
Checked for update of app “systemtags” in appstore
Checking for update of app tasks in appstore
Checked for update of app “tasks” in appstore
Checking for update of app theming in appstore
Checked for update of app “theming” in appstore
Checking for update of app twofactor_backupcodes in appstore
Checked for update of app “twofactor_backupcodes” in appstore
Checking for update of app updatenotification in appstore
Checked for update of app “updatenotification” in appstore
Checking for update of app workflowengine in appstore
Checked for update of app “workflowengine” in appstore
Starting code integrity check…
Finished code integrity check
Update successful
Turned off maintenance mode
Reset log level
Check indices of the share table.
Adding additional owner index to the share table, this can take some time…
Share table updated successfully.
Adding additional initiator index to the share table, this can take some time…
Share table updated successfully.
Backup stored at /var/www/nextcloud/data/ncp-update-backups/nextcloud-bkp_20190122_1548185256-14.0.4.2.tar.gz
Clean up…
Following columns will be updated:

* filecache.mtime
* filecache.storage_mtime

This can take up to hours, depending on the number of files in your instance!

Any ideas?

I finally did the update from within nextcloud, Settings/Overview.
Just finished and it seems to work however i got some notifications about missing tables in the database which can be fixed manually, according to the message.

nc-update-nextcloud gave a message once about not being able to update between major versions.

I have a similar problem. I am on a shared hosting, did the webupdater, finished successfully. After logging out the admin, I cannot browse to the regular login page. It just shows a error with the internal server error.

The log says this:

  • Typ: RuntimeException
  • Code: 0
  • Message: File entry could not be inserted but could also not be selected with getId() in order to perform an update. Please try again.
  • File: /www/xxx/nextcloud/lib/private/Files/Cache/Cache.php
  • line: 297

#0 /www/nextcloud/lib/private/Files/Cache/Cache.php(232): OC\Files\Cache\Cache->insert(‘appdata_ocs95no…’, Array)
#1 /www/nextcloud/lib/private/Files/Cache/Scanner.php(292): OC\Files\Cache\Cache->put(‘appdata_ocs95no…’, Array)
#2 /www/nextcloud/lib/private/Files/Cache/Scanner.php(221): OC\Files\Cache\Scanner->addToCache(‘appdata_ocs95no…’, Array, -1)
#3 /www/nextcloud/lib/private/Files/Cache/Scanner.php(336): OC\Files\Cache\Scanner->scanFile(‘appdata_ocs95no…’, 3, 530, false, true)
#4 /www/nextcloud/lib/private/Files/View.php(1324): OC\Files\Cache\Scanner->scan(‘appdata_ocs95no…’, false)
#5 /www/nextcloud/lib/private/Files/View.php(1368): OC\Files\View->getCacheEntry(Object(OCA\Files_Trashbin\Storage), ‘appdata_ocs95no…’, ‘/appdata_ocs95n…’)
#6 /www/nextcloud/lib/private/Files/Node/Root.php(198): OC\Files\View->getFileInfo(’/appdata_ocs95n…’)
#7 /www/nextcloud/lib/private/Files/Node/Folder.php(133): OC\Files\Node\Root->get(’/appdata_ocs95n…’)
#8 /www/nextcloud/lib/private/Files/AppData/AppData.php(107): OC\Files\Node\Folder->get(‘activity’)
#9 /www/nextcloud/lib/private/Template/SCSSCacher.php(190): OC\Files\AppData\AppData->getFolder(‘activity’)
#10 /www/nextcloud/lib/private/Template/SCSSCacher.php(138): OC\Template\SCSSCacher->isCached(‘15ac-964d-style…’, ‘activity’)
#11 /www/nextcloud/lib/private/Template/CSSResourceLocator.php(109): OC\Template\SCSSCacher->process(’/www/htdocs/w01…’, ‘css/style.scss’, ‘activity’)
#12 /www/nextcloud/lib/private/Template/CSSResourceLocator.php(84): OC\Template\CSSResourceLocator->cacheAndAppendScssIfExist(’/www/htdocs/w01…’, ‘css/style.scss’, ‘activity’)
#13 /www/nextcloud/lib/private/Template/ResourceLocator.php(78): OC\Template\CSSResourceLocator->doFind(‘css/style’)
#14 /www/nextcloud/lib/private/TemplateLayout.php(286): OC\Template\ResourceLocator->find(Array)
#15 /www/nextcloud/lib/private/TemplateLayout.php(195): OC\TemplateLayout::findStylesheetFiles(Array)
#16 /www/nextcloud/lib/private/legacy/template.php(211): OC\TemplateLayout->__construct(‘user’, ‘files’)
#17 /www/nextcloud/lib/public/AppFramework/Http/TemplateResponse.php(157): OC_Template->fetchPage(Array)
#18 /www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php(119): OCP\AppFramework\Http\TemplateResponse->render()
#19 /www/nextcloud/lib/private/AppFramework/App.php(118): OC\AppFramework\Http\Dispatcher->dispatch(Object(OCA\Files\Controller\ViewController), ‘index’)
#20 /www/nextcloud/lib/private/AppFramework/Routing/RouteActionHandler.php(47): OC\AppFramework\App::main(‘ViewController’, ‘index’, Object(OC\AppFramework\DependencyInjection\DIContainer), Array)
#21 [internal function]: OC\AppFramework\Routing\RouteActionHandler->__invoke(Array)
#22 /www/nextcloud/lib/private/Route/Router.php(297): call_user_func(Object(OC\AppFramework\Routing\RouteActionHandler), Array)
#23 /www/nextcloud/lib/base.php(987): OC\Route\Router->match(’/apps/files/’)
#24 /www/nextcloud/index.php(42): OC::handleRequest()
#25 {main}

Anybody with a hint what this means and how it can be solve would be ver much appreciated :slight_smile:

It is not recommended to use the Nextcloud updater, if you use the NCP updater you won’t run into those issues

After a few other things that didnt lead to a solution i started from scratch.
I reset the Nextcloud 15.02 that wasnt working and did all the settings manually.

So now i have a brand new NC 15 with the same settings as the old one… :wink:

Not the solution i was hoping to find but is was only 1 hour investment so that is ok for me.

@damole1984 May I ask, what exactly do you mean with “did all the settings manually”? I am now on the brink of installing 15.0.2 from the scratch and then try a php-script to get a rescan of the data folder (I cannot ssh the server as root).

Well, I did a quick reinstall with a blank database for nextcloud 15.0.2. and now everything is smoothly running again. As I have been setting it up with the same user and groups, also my data was immediately back in the accounts.

Same issue here:
Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

I updated the NCP to 1.4.6 and then started nc-update-nextcloud.
Now I’m stuck here.
The NCPi interface is working.
Nextcloud seems to be available to the caldav clients.
Apparently the NC webserver is fubar.
Looking for the log now and will attach it later.
Edit:
I would like to use the NCP option to open a smb share so I can download the logs.
Where can I edit the settings which directory will be shared?
Edit2:
Found this https://ownyourbits.com/2017/04/13/share-your-files-in-your-lan-with-nfs/
Will see if this still works with the latest NCP.
Edit3:
Here is the ncp-report.
Tell me if you need more!

@bunducafe Thats exactly what i did. Just 3 users here so no big deal for me. I Just had to reconnect the apps and set up the automatic upload from my smartphone again.

Any ideas how to fix the issue besides installing from scratch?

Letest Update
NextCloudPi is 1.6.0 now.
NextCloud 15.0.4
I was hoping this update would fix the issue:

   Internal Server Error
   The server encountered an internal error and was unable to complete your request.
   Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
   More details can be found in the server log.

Still waiting for a fix or some advice how to repair the issue.

Edit:
Any clues in the apache2/error.log.

[Sun Feb 10 10:03:17.001504 2019] [core:notice] [pid 1201:tid 3069468672] AH00094: Command line: '/usr/sbin/apache2'
[Sun Feb 10 10:04:12.503318 2019] [mpm_event:notice] [pid 1201:tid 3069468672] AH00493: SIGUSR1 received.  Doing graceful restart
[Sun Feb 10 10:04:12.597844 2019] [ssl:warn] [pid 1201:tid 3069468672] AH01909: localhost:4443:0 server certificate does NOT include an ID which matches the server name
[Sun Feb 10 10:04:12.598475 2019] [ssl:error] [pid 1201:tid 3069468672] AH02217: ssl_stapling_init_cert: can't retrieve issuer certificate! [subject: CN=bananapim2 / issuer: CN=bananapim2 / serial: 95819A10DFD438A0 / notbefore: Dec 15 19:30:17 2018 GMT / notafter: Dec 12 19:30:17 2028 GMT]
[Sun Feb 10 10:04:12.598549 2019] [ssl:error] [pid 1201:tid 3069468672] AH02604: Unable to configure certificate localhost:4443:0 for stapling
[Sun Feb 10 10:04:13.001382 2019] [mpm_event:notice] [pid 1201:tid 3069468672] AH00489: Apache/2.4.25 (Debian) OpenSSL/1.0.2q configured -- resuming normal operations
[Sun Feb 10 10:04:13.001502 2019] [core:notice] [pid 1201:tid 3069468672] AH00094: Command line: '/usr/sbin/apache2'
[Sun Feb 10 10:14:54.230973 2019] [proxy_fcgi:error] [pid 9489:tid 2757297200] [client 192.168.178.152:57569] AH01071: Got error 'PHP message: PHP Notice:  Undefined index: app in /var/www/ncp-web/index.php on line 214\n'
[Sun Feb 10 10:24:24.574287 2019] [proxy_fcgi:error] [pid 9489:tid 2899952688] [client 192.168.178.152:57710] AH01071: Got error 'PHP message: PHP Notice:  Undefined index: app in /var/www/ncp-web/index.php on line 214\n'
[Sun Feb 10 15:31:34.584034 2019] [mpm_event:notice] [pid 1201:tid 3069468672] AH00491: caught SIGTERM, shutting down
[Sun Feb 10 15:31:34.815158 2019] [ssl:warn] [pid 19799:tid 3069976576] AH01909: localhost:4443:0 server certificate does NOT include an ID which matches the server name
[Sun Feb 10 15:31:34.815644 2019] [ssl:error] [pid 19799:tid 3069976576] AH02217: ssl_stapling_init_cert: can't retrieve issuer certificate! [subject: CN=bananapim2 / issuer: CN=bananapim2 / serial: 95819A10DFD438A0 / notbefore: Dec 15 19:30:17 2018 GMT / notafter: Dec 12 19:30:17 2028 GMT]
[Sun Feb 10 15:31:34.815685 2019] [ssl:error] [pid 19799:tid 3069976576] AH02604: Unable to configure certificate localhost:4443:0 for stapling
[Sun Feb 10 15:31:35.077166 2019] [ssl:warn] [pid 19800:tid 3069976576] AH01909: localhost:4443:0 server certificate does NOT include an ID which matches the server name
[Sun Feb 10 15:31:35.077651 2019] [ssl:error] [pid 19800:tid 3069976576] AH02217: ssl_stapling_init_cert: can't retrieve issuer certificate! [subject: CN=bananapim2 / issuer: CN=bananapim2 / serial: 95819A10DFD438A0 / notbefore: Dec 15 19:30:17 2018 GMT / notafter: Dec 12 19:30:17 2028 GMT]
[Sun Feb 10 15:31:35.077694 2019] [ssl:error] [pid 19800:tid 3069976576] AH02604: Unable to configure certificate localhost:4443:0 for stapling
[Sun Feb 10 15:31:36.006908 2019] [mpm_event:notice] [pid 19800:tid 3069976576] AH00489: Apache/2.4.25 (Debian) OpenSSL/1.0.2q configured -- resuming normal operations
[Sun Feb 10 15:31:36.007227 2019] [core:notice] [pid 19800:tid 3069976576] AH00094: Command line: '/usr/sbin/apache2'
root@bananapim2:/var/log/apache2#

check the output of sudo ncp-report for clues

I uploaded the ncp-report.
Would you mind having a look at it @nachoparker ?
I don’t know what is right and what is wrong.

all the services are up. You could investigate the nextcloud log errors. The one about the tmp dir is ok but you could create the dir and set the ownership to www-data