Can you post the db.log file? Note that this is a different file from the debug.log file. It is named db.log and can be found in the same directory as the wallet.dat file.
yes I know there is a db.log but its empty
0.20.1 is now synchronized and runs without problem.
I will keep it for now as it is also faster connecting and syncing on startup, I just want to report this error.