I'm on xbox. What I define as a corrupt save is when the game rolls back then won't allow you to load beyond it. For example, I fly a mission and the save glitches me back before I flew the mission, so I try it again, save and it rolls back. Seems if you wipe your saves(can't delete persistent) and force the persistent to overwrite by changing your science score or hiring a kerbal it allows you to carry on. I have a minmus colony with 3 large crafts and 2 rovers as well as an orbital station that's getting big. There is definitely fps lag. I should mention that when the game freezes I wipe ALL the saved data from the console and download it from the cloud, seems to stop the freeze from dooming your save.