I'm playing Skyrim on PC. After finishing Dawnguard DLC, Serana doesn't have a "I need you to do something" option. However if you hold onto the button that talks to her, it shows up. This is where the bug starts. I can't exit this follower command mode. ESC or TAB doesn't work, Traveling, dismissing her doesn't work either. I can't do anything to get out of this mode and I don't have a previous save file without this bug.

How can I fix this bug?

The only possible fix is if there was a "I need you to do something" option for her but I can't find this fix.