The issue is likely that you already have two computers registered.
For the convenience of our users we allow for up to TWO simultaneous installs on separate computers. This means that you may install one copy of CTA3 on two separate computers without issue providing only one computer is in use at any one time.
If you then wish to install on a new computer you can simply uninstall from an old computer while connected to the internet and this will free up your license.
However if you are not able to uninstall because of say hardware issues, you can manually deactivate from one of the two computers you currently have registered.
So please follow the steps below to deactivate your license from an old computer and this should allow you to launch CTA3 again.
1. Login to your Member Account.
2. Switch to the Registration page.
3. Check the "Activated Number" column. If your products show 2 then you need to deactivate.
4. Click the "Details" link in the Activated Number column.
5. Scroll down to see the computers currently activated.
6. Click the "Deactivate Now" link to remove a computer.
7. You should now be able to install or launch CTA3 again.
I hope this helps.
Peter
Forum Administrator
www.reallusion.com