IDE won't load: Access-Control-Allow-Origin


Opening c9, or if it is open trying to open or save a file a file results in the spinning wheel of death, or the workspace won’t even load. Developer console shows:

If I wait a few minutes the problem goes away, only to reappear a few minutes later. I see that this topic has been opened in the past with no clear answer other than clearing the browser cache (which works for me but only for a few minutes). If I wait a couple minutes I am usually able to save or open a workspace, only to have this error pop up again a few minutes later… Any ideas?