Posted by When there is a password change, this message can appear. In this situation you cannot make any changes or if it is a private repository even make a clone or pull.
Luckily there is a quick solution:
Navigate to:
Control Panel\All Control Panel Items\Credential Manager
Or:
rundll32.exe keymgr.dll,KRShowKeyMgr
Remove the git entry and try again (now you will be asked again for your username and password).
Voila!