So a while ago I got the 0/nan stamina glitch and I deleted some mods and I reloaded the save where I did not have this problem but I don't really save a lot, I was doing the game style where I only save after completing something REALLY hard so I had to start the whole dawnguard DLC again. I was doing the chasing echoes quest and I lost Serana I looked everywhere and could not find her so I opened up the console and wrote "player.placeatme (Serana's ID, Can't remember it and cant be asked to look it up)" And Serana came next to me except she was not wearing the nightingale Armour I gave her. When I talked to her I clicked manage with AFT and she just wandered off, If i pull my weapon out she will pull hers out but If i crouch she does nothing. I can't continue the quest without her because she needs to open the portal to the soul carin. PLEASE HELP!!

Basically you spawned a clone of Serana. You shouldn't use the "placeatme" command on an NPC. Disable the clone/copy you spawned and use the "moveto player" command instead. You'll need to use her RefID# so try "prid xx002b74" where xx=load order for Dawnguard (probably 03 so 03002b74). Then type "moveto player" and that will move the real Serana to your location.

Start a new game. Deleting or unistalling mods mid game is a no-no.