We spent a lot of the morning and after lunch working on the issue and finally uncovered the problem: our group policy had some of the software required by Ignition blocked by a program called AppLocker. Why it wasn’t an issue on the previous gateway machine, I am not sure - I’d assume that machine had some privilege that the new gateway did not.
When he figured out how to see the blockages, he was able to whitelist the software in our group policy and the issue was resolved.
Thank you and your team for your help.