Facing Internal Server Error

My NC instance is installed with snapd on fedora 35 server ( NC snap version 22.2.3 )

After a power cut, my NC does restart correctly.There is an error message displayed
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.

And I tried the following command

sudo nextcloud.occ maintenance:mode --on

An unhandled exception has been thrown:
Doctrine\DBAL\Exception: Failed to connect to the database: An exception occurred in the driver: SQLSTATE[HY000] [1045] Access denied for user ‘nextcloud’@‘localhost’ (using password: YES) in /snap/nextcloud/30258/htdocs/lib/private/DB/Connection.php:87
Stack trace:
#0 /snap/nextcloud/30258/htdocs/3rdparty/doctrine/dbal/src/Connection.php(1519): OC\DB\Connection->connect()
#1 /snap/nextcloud/30258/htdocs/3rdparty/doctrine/dbal/src/Connection.php(1041): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /snap/nextcloud/30258/htdocs/lib/private/DB/Connection.php(237): Doctrine\DBAL\Connection->executeQuery()
#3 /snap/nextcloud/30258/htdocs/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php(345): OC\DB\Connection->executeQuery()
#4 /snap/nextcloud/30258/htdocs/lib/private/DB/QueryBuilder/QueryBuilder.php(287): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /snap/nextcloud/30258/htdocs/lib/private/AppConfig.php(361): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /snap/nextcloud/30258/htdocs/lib/private/AppConfig.php(126): OC\AppConfig->loadConfigValues()
#7 /snap/nextcloud/30258/htdocs/lib/private/AppConfig.php(317): OC\AppConfig->getApps()
#8 /snap/nextcloud/30258/htdocs/lib/private/legacy/OC_App.php(972): OC\AppConfig->getValues()
#9 /snap/nextcloud/30258/htdocs/lib/private/Server.php(692): OC_App::getAppVersions()
#10 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC{closure}()
#11 /snap/nextcloud/30258/htdocs/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility{closure}()
#12 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet()
#13 /snap/nextcloud/30258/htdocs/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query()
#14 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query()
#15 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(182): OC\AppFramework\Utility\SimpleContainer->get()
#16 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility{closure}()
#17 /snap/nextcloud/30258/htdocs/3rdparty/pimple/pimple/src/Pimple/Container.php(114): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility{closure}()
#18 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet()
#19 /snap/nextcloud/30258/htdocs/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query()
#20 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query()
#21 /snap/nextcloud/30258/htdocs/lib/private/Server.php(1079): OC\AppFramework\Utility\SimpleContainer->get()
#22 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC{closure}()
#23 /snap/nextcloud/30258/htdocs/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility{closure}()
#24 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet()
#25 /snap/nextcloud/30258/htdocs/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query()
#26 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query()
#27 /snap/nextcloud/30258/htdocs/lib/private/Server.php(2040): OC\AppFramework\Utility\SimpleContainer->get()
#28 /snap/nextcloud/30258/htdocs/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#29 /snap/nextcloud/30258/htdocs/lib/private/Server.php(439): OC\Files\View->__construct()
#30 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\Server->OC{closure}()
#31 /snap/nextcloud/30258/htdocs/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility{closure}()
#32 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet()
#33 /snap/nextcloud/30258/htdocs/lib/private/ServerContainer.php(136): OC\AppFramework\Utility\SimpleContainer->query()
#34 /snap/nextcloud/30258/htdocs/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\ServerContainer->query()
#35 /snap/nextcloud/30258/htdocs/lib/private/Server.php(1403): OC\AppFramework\Utility\SimpleContainer->get()
#36 /snap/nextcloud/30258/htdocs/lib/base.php(594): OC\Server->boot()
#37 /snap/nextcloud/30258/htdocs/lib/base.php(1087): OC::init()
#38 /snap/nextcloud/30258/htdocs/console.php(48): require_once(’…’)
#39 /snap/nextcloud/30258/htdocs/occ(11): require_once(’…’)

I am totally lost front this issue. Please May someone help me ?

hello everybody,
I am still looking for help.

I do not understand why suddenly Nextcloud cannot connect to mysql.
My sql DB is still up, snap.nextcloud.mysql.service is well started.

I have neither change the db password since the initial Nextcloud snap install ; so I do not understand why the DB connection is broken.

Maybe something went wrong during a snap upgrade ?
This is my actual snap status : sudo snap list
Name Version Rev Tracking Publisher Notes
core18 20220428 2409 latest/stable canonical✓ base
nextcloud 23.0.3snap1 30258 latest/stable nextcloud✓ -
snapd 2.55.3 15534 latest/stable canonical✓ snapd

Can something be broken between a snap update from 29223 to 30258 snap revision ?

Please can someone help me ??

I have checked the /var/snap/nextcloud/29929/nextcloud/config/config.php and the /var/snap/nextcloud/30258/nextcloud/config/config.php

There is no difference between, except the version (normal)
sudo diff /var/snap/nextcloud/30258/nextcloud/config/config.php /var/snap/nextcloud/29929/nextcloud/config/config.php
42c42
< ‘version’ => ‘23.0.3.2’,

‘version’ => ‘23.0.2.1’,

So dbpassword has not been change between snap upgrade from 23.0.2.1 to 23.0.3.2
I do not understand why Nextcloud complains about the DB connection.
It should work.

Any idea ??

Hello everybody,

I finally performed a snap revert, and my Nextcloud instance immediatly came back to life !

sudo snap revert nextcloud

Something goes wrong with the snap upgrade from 23.0.2snap1 to 23.0.3snap1

Now I am not confident into this upgrade ; there is somtehing wrong with the database and must be investiguate.
Could the Nextcloud Support take care of my issue ?

Best Regards

Hi there! have you found the solution? Is there anything that has worked for you?

Hello,

No solution except roll back to the previous snap version (23.0.2snap1 29929).

I have no idea how things will come with another update to 23.0.3snap1 30258.