Well I now just got the Louis Letrush clone glitch outside Whiterun, and with the 1.6 update my Shadowmere disappeared. Fix the Louis Letrush glitch, I can do without Shadowmere. Also I've said this before I can't do the Companions Guild questline as I was glitched by the "Hired Muscle" quest which assigned me to go intimidate Sven which was killed by a dragon before I even joined the Companions guild and has broken my game so I can't get the Achievements from playing the Companions guild and I can't become a werewolf which prevents me from using a gameplay feature which I should be able to use.