Helmsmasher

Are you using a custom race?

You uploaded the image under supporter images so I can't see it.

Try disabling autosave.

Loot only looks at masters, not really a great tool for bigger mod lists. It should be fine to put her at the bottom of your loadorder.

try setstage DLC1HunterBaseIntro 70 or setstage DLC1HunterBaseIntro 200

It is the opposite! Quicksaves and autosaves cause save bloat! Avoid auto saving and quicksaving ever at all cost! Too many quick/auto saves can leave a save permanently bloated and unloadable!

Install the required mods for the preset you are trying to use.

Delete your data folder then use the repair function in steam. You can't magically have a letterbox, there is a file that is doing this. That or you have the wrong resolution set.

Unpack your .bsa files, replace the elven armor meshes and textures with these (rename them to the elven armor file names)

So you get a letterbox without any mods activated? Sounds like you either didn't properly uninstall ENB or have the wrong resolution settings then.

Is it last in your loadorder?

Remove the new mods you added one by one or in small groups to find it.

Next time read the mod description. It has a list of all the incorporated changes and fixes. It for example includes this fix: https://www.nexusmods.com/skyrim/mods/76607?tab=files

When you say teleporting, do you mean transported by the quest or actually teleporting with console commands?

Did you go upstairs to talk with Serana and Isran?

Did you install texture packs from LE onto SE?

https://www.nexusmods.com/skyrimspecialedition/mods/5658 https://www.nexusmods.com/skyrimspecialedition/mods/14580 etc. Use the searchbar it's all there

This. It sounds very much like you aren't using a clean save. And the problem could be an incompatibility between your mod and USSEP, it certainly is not a problem with my player homes and I have been using USSEP since it's release.

Yeah. here's a tip: don't install 300 mods at once and expect them to work. Install them in smaller groups, no bigger than 10, and then do a testrun. That way it is far easier to find which one is the culprit.

Well it's not USSEP causing the issue or I would have the issue as well.

Do you have many items stored in the player home? That is what causes this bug afaik, mannequins are loaded in after the items so they won't settle down for a while. One solution I found is to not use playerhomes as storage places. I just use followers for storage. Never had mannequins moving for me since.

Technically you are dragonborn as well, basically a demi-god, you are going in through a dragonpriest portal and survive because you are a dragon.

Are you using a new save game for the new modlist or are you using the old save? Many mods can't be safely uninstalled without leaving records behind. It's why I always tell people to complete their modlist and stick to it, not changing it until the playthrough is finished.

Simple outfit manager as Gorsha said, beautiful little mod.

https://www.nexusmods.com/skyrimspecialedition/mods/1310 https://www.nexusmods.com/skyrimspecialedition/mods/21729