If you try logging into Bing Webmaster Tools, you will be greeted by a message that reads "We are experiencing an issue processing your request at this time." But Bing does tell you that the "Webmaster Center Team has been notified of the error and will work to resolve it. Try again in a few minutes." But trying again in a few minutes won't help, because it has been an issue over the weekend.
The issue seemed to have started yesterday, Sunday, at 5am (EST). Here is a picture:
This comes less than a month after the Bing Webmaster Tools add site bug that wouldn't allow webmaster to add or validate sites on the tool.
Bing has yet to confirm the issue, but I assume as the team (who I believe is based in Seattle -8 GMT) comes into the office today (today is Columbus day) they will get to fixing it.