Please help me, i purchased an ad-free Dolphin license for my site but
i cannot register my domain name for the license. I entered the license
code into my Admin panel, but the Dolphin ad & logo still appears.
I also purchased the ad-free Ray A/V Chat license and my domain name is registered for it and it works (no Ray ad or logo).
Someone please help, thanks.

you can try than to get the prompt. Also you can check it by putting the phpinfo.php in the admin folder and call to it from www.your_domain.com/admin/phpinfo.php and check if it's on or off!