I need to upgrade from 2.2.3 to the latest version 2.6.x
When I do the import as usual (of course everything is backed up)
I disable all plugins, then run the upgrade. I see that all the tables in the database have been updated but now my categories no longer appear.
There are no modifications to the WordPress core files, and the plugins did not modify the core files or table structure either. 2.2.3 is the latest version I cna upgrade to without this becoming a problem.
I have seen a few posts about this problem but all of them trace back to a faulty plug in which can't be my problem since all 3 of mine are disabled at the time of upgrade.
Suggestions? I'm very comfortable running SQL queries if needed.