Tap Form 5 crashes while reading backup-file

Hi,
this morning i bought the new Tap Forms 5 app and tried to migrate from Tap Forms 4 to the new Version on my iPhone 6.
A Backupfile was build (about 716,9 MB) and i am able to chose this in Tap Forms 5. I also entered the key with which my database in Tap Forms 4 was encrypted.
The migration starts but after a while crashes while trying to import a form which has more than 2000 entries :-(
The forms are all created in Tap Forms 5 but a lot of Data is missing. Not event the formular where the crash took place but also formulas where the migration process said “done” where empty (as far as i find out these are forms that are using pictures).
Any help would be great!
Thanks a lot,
Matthias