All mods removed, packages deleted from the server. uploaded SMF 2.0 RC1 large upgrade, SMF English-utf8 & Danish-utf8 language packs.
I've tried this 4-5 times over the last week. I still can't change language, but it saves the setting. No errors in the log.
It's a test forum, so nothing can get lost.
Strange, I've tested this alot in the last day or to ESPECIALLY with danish after our other bug reports?
Although I usually have cache disabled. Are you using cache? Does emptying it help? (I wonder if its not clearing cache)
Are you changing it in admin or via profile? If profile are you allowing your users to change language in admin.
Yeah, I've cocidered all those issues.
I just went to "Enable user-selectable language support", enabled it, saved, disabled it, saved, and now it's working.