It says clearly that there is an installation of their software with your license on another web. Remove the installation from the old web and try again. And also, press "Change Licensed URL".
You cannot have 2 installations of IPS Software on 2 different websites.
You can have 1 main installation and also 1 test installation.
Example:
www.yourcommunity.com - would be the main one.
www.yourcommunity.com/test - would be the test installation.