If you have issues after creating a user, make sure that the user you have created and the password assigned are typed correctly. Having CAPS Lock turned on can change everything when it comes to the log-in procedure. Try creating another username and watch the status of the Caps Lock. If after this operation you still encounter login issues, you might need to get in touch with the developer because this could be a bug in the application which prevents you from logging in with newly created credentials.
