I found this while perusing the net and decided to share, it worked for me, it should work for you too, enjoy!
1. First download camtasia 9 trial:
2. Install the trial but don’t put the activation key in or register the product.
(after installation close out of camtasia)
3. Disconnect your internet connection
4. Find reginfo file: C:\ProgramData\Techsmith\Camtasia Studio 9 in RegInfo.ini
open the regInfo.ini and copy/paste this below[RegistrationInfo] ValidationData3=1
To stop camtasia from editing this file:
1. Right click on RegInfo.ini
2. Select “Properties”
3. Check “Read-only”
4. Click OK to save.
After you’ve done all the steps you can reconnect to your internet and use camtasia. Let me know if it worked for you too.