if you use a repository_server thats not done in an inmemory table
and you created that repository_server with a 2020.09 release then it could be that when upgrading to 2020.12 you will get a "upgrade repository" button on the admin page.
But that then bombs out with a primary key violation if that is the case you can fix that by running this statement first:
update servoy_user_properties set property_value = 53 where name = 'repository_version' (and property_value = 52)
because you are already on a repo version 53 but the the whole system doesn't know that yet.