[wrvond]

If the camper is badly out of level I've got a pair of Anderson levelers and I use pressure treated 4x4's under the leveling legs. If you've got a red light you need to run the leveling legs and landing gear all the way up to reset, then run them down and then select auto level.
As RollaMo pointed out, the out of stroke error is when your levelers can't reach the ground.