Sqlite3 to mariaDB conversion with Seafile server 8.0.4

Hello everyone!
I’ve been using Seafile for quite some time now, and I would finally like to move from sqlite to mysql/mariadb.
In order to not compromise my productive environment, I gave this a try in a virtualbox.
So I setup a new seafile server with sqlite3 and then tried to convert it with the provided script in the manual.
I already figured that I need to replace the command python with python3 within the bash script.
However, I still get a lot of errors during the conversion, especially with the seahub.db and the server has hiccups after changing the configuration, in particular seahub starts up but i cannot login anymore.

Any ideas what’s going on?
Are there some other modifications required to adjust for python3?
and how do I avoid all these errors during conversion?

Thanks a lot,
Ruediger