Kronos572

Does anyone know how to remove an NPC from a faction and correctly save and push it to the game? I can get to an NPC's file, go into the "factions tab" and delete the faction I want to remove. Save the file giving it a new name. However when I get it saves as an ESP and it pushes to Vortex I get the following error " Plugins not sorted because "filename.esp" is not a valid plugin. How do I fix that?