Avast IS License Problem on Windows 10

[REDACTED]

I uninstalled Avast IS via the Control Panel.
Then, I Ran the Avast! Uninstall Utility (http://files.avast.com/iavs9x/avastclear.exe)
Downloaded and installed the latest Avast IS (http://files.avast.com/iavs9x/avast_internet_security_setup.exe)
When I try to install my license file, I get the following error:

Unable to insert the license file.
The license is not valid for this product.

This licsense file was working fine on Windows 8.1.

I'm getting this error ever since I upgraded to Windows 10 Pro.

What to do? 

[Asyn]

Try: https://www.avast.com/resend-license-paid.php

[REDACTED]

I purchased Avast! IS license from a reseller.

[Asyn]

I purchased Avast! IS license from a reseller.

You've to contact the reseller then.