[sciurius]

On tablet, all files are not managed by MSPro. Storage location is SDcard.
All files reside under the Android/data/com.zubersoft.mobilesheetspro/files folder.
I make a backup to Google Drive.

On phone, all files are not managed by MSPro. Storage location is SDcard.
I restore the backup from Google Drive, to original locations.
Upon completion there is a message that some files could not be written due to file permissions or path mismatches.
I perform a Settings > Check missing files.
It reports 3 missing files. (The other 2 missing files are zero size and not copied)

   

The 3 missing files, 2 of which are visible in the screenshot (top entries), refer to storage location C443-17EE which is the storage location of the tablet. However:
- these files are not on the tablet (although they once were)
- they are not in the database on the tablet
- they are not in the backup file

When the backup file is restored on the phone, everything is wiped, isn't it?
- these files are not on the phone (although they once were)
- these files are not in the database on the phone
Where does the 'missing' information come from?

I stop MSPro and restart it, and again perform a missing file check. There are now 6 files missing. Huh? The 3 missing files above are disappeared.

Could it be that the database wipe is not sufficiently dealt with, or that parts survive in a cache?

Among the missing files is Partituren/Afasiekoor/10_Sinterklaas.cho. Sounds familiar? That's right, this is song with id 10, but I thought the stripping of the numeric prefix was fixed in 2.3.0?

Then I decided to uninstall MSPro, verified there were no leftover files, and reinstalled from Google Play.
I set it to not manage the files, storage location on SDcard, expose database.
I restored the backup again.
Everything went flawlessly. Checked for missing files: nothing is missing. All songs are shown in the overviews (songs, collections, ...)
Close MSPro and restart, checked again: all song files are missing.
In /storage/XXX-XXX/Android/data/com.zubersoft/mobilesheetspro/files is only mobilesheets.db. No song files.

Tried again: same.
When it said no files are missing, I tried to actually view a song and got the message that the file was missing. Checked again: all song files missing.
Tried again: same.
Tried again: now all files are really restored.
Tried again: now all files are really restored.

There is something wrong here, and I'm not sure it is MSPro...