[CReinhardt]

I got many faults like this
04:06:29 nachm. - Song yesterday wird verglichen
04:06:29 nachm. - Fehler: java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.String group.pals.android.lib.ui.filechooser.f1.d.getAbsolutePath()' on a null object reference
04:06:29 nachm. - Das Zusammenführen der Bibliothek konnte nicht erfolgreich beendet werden.

What.happened?

[Zubersoft]

That means MobileSheets is trying to access a file, but that file either doesn't exist or is inaccessible. Are you synchronizing between devices or to the cloud? If you go to Settings->Other Settings->Find Missing Files, do you have any files missing in your library? If you are synchronizing to the cloud, did you modify the sync folder in any way?

Mike