I'm currently playing the main story of the Dragonborn DLC with my Khajiit character. I've just exited Bloodskal Barrow (doing "The Final Descent" sidequest for Crescius Caerellius). And when returning to Raven Rock, Mogrul, Slitter, and Captain Veleth start attacking me for no reason. I have not attacked them nor any other NPC in Raven Rock, or any non-hostile NPC on Solstheim for that matter. I have not stolen anything from any of them, and I have no bounty in Raven Rock. Any one know a fix for this?
Try to avoid the town for two days. Any form of hostility goes the same way. Just go outside of town, where you know one of the people affected by the bug will go, and wait for two days (Use the wait button for this, of course.) This should clear all hostilities up.
PS: It's always better to wait an extra day or two to make sure all of the hostilities clear up completely.