Link to a page where the issue can be seen: back end only
I've cleared the GUID cache
also fixed orphaned intermediary port types
and deleted leftovers
I expected to see: no errors
Instead, I got: > The upgrade process is starting...
> Precondition "correct database layer mode"... OK
> Precondition "toolset_associations table exists"... OK
> Precondition "toolset_associations_old table is not yet present (indicates manual database manipulation)"... OK
> Precondition "toolset_associations_new table is not yet present (indicates interrupted upgrade process)"... OK
> Precondition "toolset_connected_elements table is not yet present"... OK
> Precondition "able to create a new database table"... OK
> Precondition "able to delete a database table"... ERR
It looks like you have some server restrictions which mean your site doesn't meet the conditions for being able to perform the upgrade.
The upgrade process involves deleting existing relationship tables and replacing them with new ones, and before trying that the process tests whether it is possible with a temporary table intended to be disposed of.
Here's the code from Types that performs the check: