The Inverter does not have anything to do with the Levelers or Slides. Those are 12V circuits and the Inverter puts out 100V AC.
That being said, your Inverter not turning on and Leveler and Slides not working gives you a clue.... it points to the house batteries. Could be a bad connection.... bad house batteries.... tripped 12V breaker.
There is usually a 100A Bussman 12V breaker near the house batteries that provides circuit protection to the Levelers (and usually for starting the generator as well). If that breaker is tripped, the Levelers won't work (and the generator won't start).
Typically the Inverter is wired directly to the house batteries with its own fuse or breaker but not sure how your coach is wired. If it won't power on, then the fuse or breaker for the Inverter could be the issue.
I don't know what Inverter you have but if it is a Xantrex with a built in transfer switch, does it power up on shore power and give the fault or only when you try to run off the house batteries?