FZLC1111:A:A replacement key code has been issued and must be used with this product line

Hi
 
The normal scenario.
 
I'm very often asked to visit peoples houses because their PC's have become infected. I install the trial version of webroot SecureAnywhere, which disinfects the pc. The client is usually impressed with the product so I then go away shop around for the best deal I can find. Return to the client and enter the code that came with the purchased copy, the code is accepted and everything works as expected.
 
On this occasion.
 
I carried out the above procedure for a client with 2 pc's in their house.Installing the trial version on both pcs.  I go away and purchase a 3 user copy, I entered the code on the first pc and webroot accepted the code and activated the years subscription as expected. However when I entered the code on the second pc I received the error message - "FZLC1111:A:A replacement key code has been issued and must be used with this product line". I assume if I were to be sent a replacement code it would be sent to the email address registered at the time the trial version was installed.
 
No such replacement code has been received.
 
Any assistance would be appreciated - thanks
 
Jeremy
 
P.S. I'm in the United Kingdom