I had a problem like this before, but it was triggered because I installed a newer version of MotoSim EG (the simpler simulator) in a machine with an older version of MotoSim EG-VRC (the complete simulator). Updating EG-VRC and reinstalling EG solved the problem at that time.
Anyway, MotoSim 2022SP1 manual has a mention on this type of problem on its troubleshooting section (14.1 Start of MosoSim EG-VRC), but the solution isn't really helpful. Basically, it says to uninstall older versions of MotoSim and try again, and I believe You did it already a couple of times. But I would investigate some sort of remaining system file or registry entry after the uninstall process.