On en-beta, the left-hand Tools > Upload file link goes to http://en.wikipedia.beta.wmflabs.org/wiki/Wikipedia:File_Upload_Wizard , but this is a missing page. On en-wiki it's a complicated bit of wiki text and must be loading some specialized JS somehow. The needed files could probably be exported and imported/merged to en-beta, or the link could be changed to go to the plain Special:Upload. The latter could have some message text modified to encourage to upload to commons.wikimedia.beta.wmflabs.org (which has its own upload issues, I'll file a separate bug).

Version: unspecified
Severity: enhancement