Hi bananaann and welcome to our community
I really Really REALLY wish I had half a clue as to what to
advise you. But here's the deal. Adobe has a different department
handling the installer. So even the actual RoboHelp development
team is probably hamstrung to advise what to try. The thing is, we
are seeing the same reports for other products too. Captivate and
Visual Communicator I know for sure. I've heard reports of several
others.
I'm guessing your best bet at this point is to contact Adobe
support.
Wish I had a better suggestion to offer.
Sincerely... Rick