Changing Names
There may be reasons (for example https://www.axisandallies.org/forums/topic/32495/new-triplea-with-new-forums-user-does-not-exist-error) why you need to change your username.
For this it is important to know the concept of names on the forum.
When you are on a userâs profile you see for example something like this:

Now the first name shown is what the forum calls âFull Nameâ,
the second name shown behind the @ -symbol is the âUsernameâ.
Both names might be identical, they might be different, too.
It is important to know that the âFull Nameâ is more or less cosmetics, when different from the âUsernameâ.
The âFull Nameâ is not your log-in name, it is not your name for TripleA-games, you can not be @ -mentioned by your âFull Nameâ (when different).
You can change your âFull Nameâ to whatever (even your real name) without any consequences for your log-in or TripleA.
It can be changed, when you go to âEdit Profileâ:

So in order to change your login-name, your TripleA-games name and the name you can be @- mentioned with, you need to change your âUsernameâ:

Klick âChange Usernameâ and edit it: 
Important: Avoid to use periods, spaces or other special characters in your username as this might cause problems.