RaspberryPi upgrade Seafile 8.0.X to 9.0.2 seahub _msql error

Hi,
i have followed the upgrade instructions

manual.seafile.c0m/upgrade/upgrade_notes_for_9.0.x/

The upgrade script said “Upgraded your seafile server successfully.”

Starting the services, seahub won’t start anymore.
The error output ends with:

NameError: name ‘_mysql’ is not defined

I used the downgrade script upgrade_minor. 8.0.X still works again. What i’ve missed with the upgrade?

ok fixed. I mistakenly used the bullseye version for buster.