I recently hit a problem when attempting to access the Office 365 Portal with Chrome. Any attempt resulted in a HTTP Error 400 as shown above. The problem was confined to a single PC and a single browser on that PC as both IE and Edge were happy to connect to Office 365.
The wonders of Internet search quickly located some help and suggested that the issue was due to a corrupted cookie associated with the request.
As obvious from the screen shot, connections to portal.office.com use a lot of cookies. There’s no way to say which of the 22 cookies might be corrupt, so the easiest and quickest fix is to delete the cookies and force the next connection to recreate whatever is needed. Do this by selecting the X opposite the set of cookies and then click Done.
Ten seconds later a connection was made and the problem resolved. Isn’t it great when things fall into place so easily!
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