I am told I am pretty good at save cleaning, so I will leave you with this guide on how to clean your saves.

Unfortunately, in v0.0.1 of my mod, I broke the script and it left a dead copy of itself in saves, which can cause crashes and other nasty behaviour. It also translates EFF commands (follow, wait, relax, etc.) to the appropriate AI commands, so the AI is always synchronized with her stock follower behavior. To fix this, I made a plugin in EFF that connects to her AI and tells her to become a follower. Even if forced to become a follower again, she will continue to walk home instead of following you. However, there’s another problem: Sometimes, Serana’s AI decides to override her follower status and will force her to walk to wherever her “home” is. My mod fixes this by having a plugin remove the problematic dialogue entries. Because of this, Serana, unlike most NPCs in the game, will basically tell you to go fuck yourself if you ask her to come with you when you already have a follower. Skyrim was coded with the assumption that the player would only have one follower at a time. Unfortunately, this AI also clashes with mods like Extensible Follower Framework, which enable you to have more than one follower at a time. She’s a rather complex entity, using her own AI to help quests in Dawnguard manipulate her follower status and “lock” her to the player when needed. I recently made a Skyrim mod to fix an annoying bug with Serana, one of the Dawnguard DLC’s characters.

Best skyrim save game cleaner