While converting on localhost (previous convert from 3.4.7 was fine but template was broken) I got a error:

Unknown column 'sys_module_admin' in 'where clause'
...\OpenServer\domains\..../applications/core/setup/upg_40000/queries.json - query #4
UPDATE `core_modules`  SET `sys_module_area`=? WHERE sys_module_admin=1 

Upd: modified theme from IPBForumSkins was installed by default 

Probably there were some trash from prev. RC2 upgrade. Removed all DB, imported from 3.4.7 and started upgrade again.

How to avoid such links to old site address (I'm on localhost right now)?
Because the links my template is broken after upgrade and I can't check the forum on localhost.

 

 

Ok, next try

1. Switched to default theme
2. Removed other themes
3. Removed all hooks and apps
4. Updated
5. Replaced all wrong forum links to new one in some css files.

Now I have other problem - no one link opens. I have a SEO FURLs, so it was processed to translit from Cyrillic to English in original forum, now they are on Cyrillic and don't open (URLs like http://forum.probki.net/topic/9382-камеры-спб-и-ло/)

With another reinstall I've fixed the FURL problem, I switched to QUERY_URL in Settings of 3.4.7 because Windows.