I have been playing up till the current end of the quest Siege of Khor'minos with Brint and decided that I wanted to change him to Brienne and I went to the cave to start Mad Cow but there was no option to explore the cave. At first I thought it was because I got Brint's Ice set but I loaded an older save to see if that was the problem but that had the Ice set before I entered Khor'minos and was able to start Mad Cow and change Brint to Brienne.
I then spent a while checking multiple saves and any after entering Khor'minos weren't able to start Mad Cow but any before were able to. I even loaded a save before entering the outskirts walked went up to where you enter them saved then went back to the cave to check if I could start the Mad Cow quest and I could, I then loaded the save entered the Khor'minos outskirts then exited and went back to the cave and couldn't enter it to start the quest. I even tried this on the public version on the site on Google Chrome same outcome. I took a screen shot of what it says when I'm at the cave and it says it's inaccessible now. If this was a feature would have liked to know before hand but the randomness of it happening only after entering Khor'minos outskirts makes me think it's a bug.
I then spent a while checking multiple saves and any after entering Khor'minos weren't able to start Mad Cow but any before were able to. I even loaded a save before entering the outskirts walked went up to where you enter them saved then went back to the cave to check if I could start the Mad Cow quest and I could, I then loaded the save entered the Khor'minos outskirts then exited and went back to the cave and couldn't enter it to start the quest. I even tried this on the public version on the site on Google Chrome same outcome. I took a screen shot of what it says when I'm at the cave and it says it's inaccessible now. If this was a feature would have liked to know before hand but the randomness of it happening only after entering Khor'minos outskirts makes me think it's a bug.