Once you have activated Gig Performer on your computer, you can run it without an internet connection and quite frankly we highly recommend that you disable your network and as as many other unnecessary services/applications as possible.
Note: while Gig Performer does not require an internet connection to work once it has been activated, you may find that some plugins do require such a connection so you should check the requirements of any plugins you want to use to make sure you won’t have a problem when you get up on stage.
Click here to learn more: https://gigperformer.com/do-i-need-an-internet-connection-to-use-gig-performer/