DT does not start on iPad - Database problem

Hi DT,
I yesterday tried to start DT on my iPad, but I only see a screen which says that the database is going to be updated (see screenshot). I waited a really long time (a day), but nothing happened . Any hints?

How large is your database and do you have enough disk space on your device? If there is one, please send us the file Console.log, which you find in Files > On My Device > DEVONthink, to our customer support. Maybe we see something.