rh9 does it work when not all packs are enabled? That's a lot of languages to enable at once, there could be some sort of conflict.
The solution to that problem is usually to clear cache as described above by Ralkage
If that doesn't help, you could try disabling all third-party extensions, clear the cache, and see if it works. Then repeat while re-enabling extensions one by one to see which one might cause the problem.
If that doesn't help, you'll probably need to contact the FreeFlarum support.