After upgrading EPiServer CMS5 r2 to CMS5 r2sp2 you might get a nice little error in edit mode. This page is not available for the active language. This is due globalization changes and the workaround is to activate a language for your site. To do this do the following:
1. Go to admin mode
2. Click on [...]
So during an upgrade to EPiServer 5, I ran into this problem where the culture was wrong and all translations were being translated to English instead of Swedish, this even though the web.config was correctly changed to “sv-SE”.
After som trial and error I got to set the culture in onpreinit in the a class [...]