Conquer Skyrim episode 3: Markarth

I attack Markarth with my vampire lord form. Unfortunately I didn't wait until night, but even during the day, I can't pass through some doors. Episode 1: https://www.youtube.com/watch?v=YsLvL_7xkCw Episode 2: https://www.youtube.com/watch?v=aY9nRIIkp0I Episode 4: https://www.youtube.com/watch?v=o-Ls7WDXxQw