Just upgraded from 1.517 to 1.528 and when clicking 'Build Now' on the context menu for ALL jobs, I get the following:

"You must use POST method to trigger builds. (From scripts you may instead pass a per-project authentication token, or authenticate with your API token.) If you see this page, it may be because a plugin offered a GET link; file a bug report for that plugin."

I can understand that when you want to trigger a build remotely you can set the authorization tokens, but from the context menu it should 'Just Do It'.

I can see that this is a duplicate of https://issues.jenkins-ci.org/browse/JENKINS-16844, but this was apparently fixed in 1.509