Strange one, but I was trying to log in to my personal MSDN Azure subscription from Visual Studio 2015 in order to deploy a web app, something I've done many times before, and it asked me to refresh my credentials. However, every time I tried, I would receive the error
"We could not refresh credentials... multiple_matching_tokens_found" (or something along those lines, apologies I didn't get a screen shot).
So Googling I found the following issue which was closed as 'Not Reproducible', but in this case I could reproduce, and I followed the suggestions.
Can you try one of the following workarounds to see if your issue is resolved?
For me, the second option, deleting the credential cache worked.
I just wanted to record this somewhere as there are obviously some people suffering from this but it's unlikely to be solved.