Trying to complete the 'Trouble in Skyrim' quest for the Companions where you have to kill the Forsaken cave leader. However I killed him during another quest and now when I go to the location the quest arrow just floats above his dead body. I can't turn in the quest, and if I try to speak to anyone in the Companions for another job they tell me I already have one to do so I can't progress that quest-line.

Also found the thieves guild Numbers Job Haelgas bunkhouse to be broken, the quest arrow is in the wrong place and I can't interact with the ledger book.