"Internal Server Error" on /nextcloud/settings/admin/overview, can not update to latest version

Nextcloud version (eg, 12.0.2): 15.0.x (not sure)
Operating system and version (eg, Ubuntu 17.04): Ubuntu 16.04
Apache or nginx version (eg, Apache 2.4.25): nginx
PHP version (eg, 7.1): 7.2

The issue you are facing:
I am getting an internal error page when i navigate to the general settings page, and I am being notified for an update to version 15.0.5, but not able to do so.

I am not sure the exact version, as I can not see the general page, but I know im on at least version 15.0.0

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:
not sure how to replicate on another machine but navigating to /nextcloud/settings/admin/overview on version 15.0.x

The output of your Nextcloud log in Admin > Logging:


 0. /srv/nextcloud/3rdparty/guzzlehttp/guzzle/src/Middleware.php line 66
    create(GuzzleHttp\Psr7\Request {}, "*** sensitive parameter replaced ***")
 1. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 203
    GuzzleHttp\{closure}("*** sensitive parameters replaced ***")
 2. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 156
    callHandler(1, "*** sensitive parameter replaced ***", [GuzzleHttp\Prom ... l])
 3. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/TaskQueue.php line 47
    GuzzleHttp\Promise\{closure}("*** sensitive parameters replaced ***")
 4. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 246
    run(true)
 5. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 223
    invokeWaitFn()
 6. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 267
    waitIfPending()
 7. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 225
    invokeWaitList()
 8. /srv/nextcloud/3rdparty/guzzlehttp/promises/src/Promise.php line 62
    waitIfPending()
 9. /srv/nextcloud/3rdparty/guzzlehttp/guzzle/src/Client.php line 131
    wait()
10. /srv/nextcloud/lib/private/Http/Client/Client.php line 161
    request("get", "https://updates ... 5", {verify: "/srv/n ... e})
11. /srv/nextcloud/lib/private/Updater/ChangesCheck.php line 127
    get("https://updates ... 5", {headers: []})
12. /srv/nextcloud/lib/private/Updater/ChangesCheck.php line 73
    queryChangesServer("https://updates ... 5", OC\Updater\ChangesResult {id: null})
13. /srv/nextcloud/apps/updatenotification/lib/UpdateChecker.php line 66
    check("https://updates ... 5", "15.0.5")
14. /srv/nextcloud/apps/updatenotification/lib/Settings/Admin.php line 87
    getUpdateState()
15. /srv/nextcloud/settings/Controller/CommonSettingsTrait.php line 115
    getForm()
16. /srv/nextcloud/settings/Controller/AdminSettingsController.php line 74
    formatSettings({10: [OC\Setting ... ]})
17. /srv/nextcloud/settings/Controller/CommonSettingsTrait.php line 126
    getSettings("overview")
18. /srv/nextcloud/settings/Controller/AdminSettingsController.php line 65
    getIndexResponse("admin", "overview")
19. /srv/nextcloud/lib/private/AppFramework/Http/Dispatcher.php line 166
    index("overview")
20. /srv/nextcloud/lib/private/AppFramework/Http/Dispatcher.php line 99
    executeController(OC\Settings\Cont ... {}, "index")
21. /srv/nextcloud/lib/private/AppFramework/App.php line 118
    dispatch(OC\Settings\Cont ... {}, "index")
22. /srv/nextcloud/lib/private/AppFramework/Routing/RouteActionHandler.php line 47
    main("OC\\Settings\\C ... r", "index", OC\AppFramework\ ... {}, {section: "overv ... "})
23. <<closure>>
    __invoke({section: "overv ... "})
24. /srv/nextcloud/lib/private/Route/Router.php line 297
    call_user_func(OC\AppFramework\ ... {}, {section: "overv ... "})
25. /srv/nextcloud/lib/base.php line 987
    match("/settings/admin/overview")
26. /srv/nextcloud/index.php line 42
    handleRequest()

GET /nextcloud/settings/admin/overview
from 108.4.80.63 by c0de at 2019-03-18T21:24:34+00:00

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'instanceid' => 'oc8a8nszs7qf',
  'passwordsalt' => 'xxx',
  'secret' => 'xxx',
  'trusted_domains' => 
  array (
    0 => 'domain.net',
  ),
  'datadirectory' => '/srv/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '15.0.2.0',
  'overwrite.cli.url' => 'https://domain.net/nextcloud',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'oc_c0de',
  'dbpassword' => '',
  'installed' => true,
);

The output of your Apache/nginx/system log in /var/log/____:

none, or i cant find it.

I have same error, until now have no hint for solution this problem…