Synchronization oft the task apps with the cloud stopped working


The synchronization between the task app on my phone and the web-app stopped working awhile ago. Now I figured out that adb logcat shows following error:

5958  6060 W ActivityManager: Permission Denial: opening provider org.dmfs.provider.tasks.TaskProvider from ProcessRecord{81db5ad 4200:foundation.e.accountmanager:sync/u0a150} (pid=4200, uid=10150) requires foundation.e.permission.READ_TASKS or foundation.e.permission.WRITE_TASKS
4200 13499 W davx5   : [syncadapter.SyncAdapterService] Security exception when opening content provider for foundation.e.tasks
5958  6128 W SyncManager: failed sync operation JobId=104811 ***/ u0 [foundation.e.tasks] OTHER ExpectedIn=0s STANDBY-EXEMPTED(TOP) Reason=AutoSync, SyncResult: databaseError: true stats []
5958  6128 E SyncManager: not retrying sync operation because the error is a hard error: JobId=104811 ***/ u0 [foundation.e.tasks] OTHER ExpectedIn=0s STANDBY-EXEMPTED(TOP) Reason=AutoSync Retries=1

And the the account app shows this message:

I tried to remove and add my account again but it didn’t help.
What can I do to get the app working again?

Nevermind, I had forgotten to do a system update, yesterday I did that and know it works perfect again.