A Bing Community thread has complaints from some webmasters saying Bing Webmaster Tools is extremely buggy.
The issues reported consist of:
(1) Not being able to add new sites to the tool.
(2) Not being able to export data from the various reports.
One webmaster explained yesterday:
Others confirmed the issues are a problem on all browsers including IE, Chrome, Firefox, Opera and Safari.
I tried it myself and I had no issues. So either Microsoft fixed the issue or it is only impacting some users.
Forum discussion at Bing Community.