I have a WHMCS installation here: http://www.tarhelymost.eu/whmcs/
If somebody try to transfer a domain which is registered by another client on our server - and in the WHMCS too - than we get an error message, which says that this domain is already registered in our system, and we should delete it before we could put a new order regarding that (The domain you entered is already registered with us - you will need to cancel it prior to placing a new order).
How can I allow the transfer for my clients?
You can reproduce this problem as follows:
1. Go to the http://www.tarhelymost.eu/whmcs/
2. Click on the order button
3. Click on the Transfer domain
4. Enter misskozepiskola and .com
5. Check Availability
6. You will get the error message
Thanks for all help!