Q:

How do I connect to my Teamproject, after I changed my primary Account Alias?

A few days ago I changed my primarly alias for my Microsoft Account. Now I want to checkin my code, and get some error messages:

An attempt to communicate with Visual Studio Team Services failed because a token could not be retrieved.
You are anot authorized to access [...]

Here is a picture of it:

As suggested, I already tried re-entering my credentials. But this has no effect. I already tried closing Visual Studio, restarted my PC, but nothing helps.
How can I solve the problem?

A:

I solved the issue by deleting the following folder after I have closed Visual Studio:
%LOCALAPPDATA%\.IdentityService

Then I opened Visual Studio again, and clicked Manage Connections:

Finaly I have connected again to my Microsoft Account, restarted Visual Studio and was able to check in my code.

