[Zubersoft]

That usually points to the stamp files being missing for some reason. If you go to the storage location on your Android device (/storage/emulated/0/Android/data/com.zubersoft.mobilesheetspro/files by default but can be found under Settings->Storage->Set MobileSheets Storage Location), you will see a stamps directory. Copy that folder to the same location on your e-ink device and that should (in theory) resolve the missing file issue you are currently seeing.

Mike