Eleven rack expansion pack serial "already activated"

[pieroft]

I used to have PT and ER installed on my windows pc.

Now, i recently bought a mac computer.

I was trying to instal ER expansion pack on my mac computer, when it tells me that the serial number is already activated, and it only can be use on 1 computer.

How can i install ER expansion pack on my mac?

thanks for your help guys,


if you need more info let me know, but I know I do not have any software related issues.