I just ran into this. Here's how I got around it. (from someone else)
Open Armory Crate
Click on the User Center button (2nd from the bottom with an outline of a person)
Instead of clicking on your account on the right side of the screen, click "Sign in with another account"
Enter your credentials (feel free to click "remember me") and click the "sign in" button
After loading for a sec, you should be signed into Armory Crate again