I am having the same problem. This is the last thing holding up my return, and I've been trying to submit all day. I can't get it to work on any browser and tried to delete cookies and cache on 3 different browsers. I spent 30 minutes on hold to talk to someone on the phone because the call-back option doesn't work - it either ends immediately, or I answer, nobody is there, and after several seconds the call ends. I don't understand how I'm supposed to complete the return? Ugh.
