After upgrading to NC15, nextcloud keep redirecting to /apps/dashboard

I just updated from 14.0.4 to 15.0.2 and cannot access NC anymore as it keeps redirecting to /index.php/apps/dashboard

(During upgrade via web-updater it was told that dashboard will be disabled)

(detailed error description deleted)

As I just found cause and workaround, I can still leave this post here for anyone else having the same issues:

Here is how to fix it:

Trouble was caused by having the dashboard app installed AND the app “apporder”, with said dashboard set as default.

  • Dashboard app was disabled during update,
  • “defaultapp” in config.php was set to “apporder” which kept on forwarding to /index.php/apps/dashboard no matter what

To resolve this issue open config.php on your server and set
'defaultapp' => 'apporder',

and set it to any other app you have installed, e.g.
'defaultapp' => 'files', or
'defaultapp' => 'calendar',