This is a simple patch to Serana's dialogue which removes the options that check if you have a follower.  The end result?  Serana will follow you, even if you already have followers. 

Since v0.0.2, also will give equivalent commands to her AI script if you've completed her questline.  This fixes her AI trying to walk her "home", despite commands to the contrary from EFF. Even better, this does not mod her AI script, increasing compatibility with other mods.

Supports Extensible Follower Framework (EFF)

GitLab: https://gitlab.com/N3X15/Skyrim-EFF-Serana-Fix/tree/master

Removes:

• 'I'm not going to waste my time making sure your friend doesn't get killed. When it's just you and me, we can go.' in  response to "Come with me."
• 'Three's a crowd. Get rid of your other friend, and I'm yours.' in response to "Come with me."
• 'I don't want to step on anyone's toes. Come back to me when you're alone.' in response to "Come with me."
• 'Not until you get rid of whoever your other friend is.' in response to  "Come with me."
  

Installation:
Mod Organizer:

• Click the NMM Installer link above or on the file page.
• Double-click the file in your MO download tab after it finishes installing.
• If you have EFF, enable the EFF plugin.
  
  

NMM: Probably the same. You should really use Mod Organizer, though.

Upgrade Notes:

0.0.2 to 0.0.3:

The ESP was splitinto two to permit UFO/AFT users to only install the dialogue fixes.  You may need to clean your save using the procedure in the "0.0.1 to 0.0.2" section.

0.0.1 to 0.0.2:

Due to some issues with the Serana Script Kicker initialization, you may have a broken script floating around in your save, preventing the new one from initializing.  To fix:

• Download and install Save Game Script Cleaner.
• Open your latest save.
• Run Fix Script Instances, Delete All #, Clean Other, Del Broken Actives, and Clean Formlists. (Standard cleaning operation)
• Open Mod Editor, and check ONLY "EFF - Serana Fix.esp". Delete mod forms, and delete mod scripts.  Close Mod Editor.
• Open Advanced, and press "Remove Scripts attached to Nonexsistent[sic] forms" - This should remove the dead script.
• Repeat step 3.
• Save WITH BACKUP.
• Play!
  
  

Compatibility:

• Any mods that screw with Serana's dialogue may conflict.
• EFF Plugin identifier is 0x2000.  I don't know of any other EFF plugins, but if they use that identifier, they may conflict.
  

License:

Available under MIT OpenSource License.  Let me know if you make any changes, might be worthwhile to incorporate them into the main mod.

DISCLAIMER: Content is my own and does not reflect the opinions or views of my employer.