If you are getting the "No Service Running" message, see this article, which is the same thing someone posted above.
https://support.iracing.com/support/solutions/articles/31000177456-local-network-access-prompt
If you are getting the "Digital Signature Failed" error, close the UI and the updater, then go to where you have iRacing installed and double-click the iRacingUpdater.exe.
