Well this jogged some memories for me.
The last classic upgrade I did was about 2 years ago.
For threads it looks to be even older than that.
I sill had a backup on my nas.
It appears that I had similar issues because I used ubb 184.108.40.206 as the first step from threads.
I recall looking for the old importers prior to 2007 with no luck.
Same goes for classic because the importers were revamped by Rick in 2007.
The hardest part in classic is due to mods.
I would have to reinstall classic to get rid of them so the importer would run.