I transferred master collection to iMac and after 10 minutes it stopped working

I am looking for help transferring my license. I have a serial number and I downloaded CS5 master collection on my new mac and put in the serial number. My MBP that I used there master collection before on was disconnected from the internet at that time so it accepted the sn on my new mac and the collection worked. I then turned the wifi back on on my MBP and the software on my iMac said it was ana invalid serial number. I then tried to deactivate my MBP and then use the sn on the iMac and that didn't take it. I tried to register it online and it said it was invalid though I could still deactivate and reactivate my MBP with it.