The admin deleted my old account. And I’ve renamed myself using the control panel:
Use your current federated account to log in. Navigate to:https://community.notepad-plus-plus.org/user/your-current-user-name/edit/username Edit the user name in the form. Click “Change Username” button.
My issue is resolved.
In the future, someone would have to create a similar forum thread to get help.
In my case, my old account had my name and no activity associated with it. So, it was an easy call to delete it.
My problem came because I’ve cut ties with Facebook. So, if you’re likely to do the same, you might come here first and associate your forum account with a new ID provider. Then you can leave the old provider.