I noticed the UI disappears when the ram usage of the game gets to 1.7gigs
It appears if you reload a game, the memory footprint gets biigger, so I don't think its correctly recycling the memory usage with will cause it to reach the cap and fail.
Its easy to recreate, just keep reloading any save game until the memory usage gets to 1.7gigs and then it will crash or fail to load the UI.