Last modified: 2014-05-09 19:51:11 UTC
This is the same root cause as bug 44063: Firefox's "watch" function is making it think that the parameter info for action=watch is already cached.
Change 132493 had a related patch set uploaded by Anomie: Allow action=watch to actually work https://gerrit.wikimedia.org/r/132493
Change 132493 merged by jenkins-bot: Allow action=watch to actually work https://gerrit.wikimedia.org/r/132493