Did you delete mods from the Launcher or manually? If you downloaded them through Nexus you will need to remove the files manually from program files. It could be caused from leftover corrupted meshes or textures that were still left in the game files even if the mods were deleted from launcher.
How do i delete them manullay
You have to go into the Skyrim file, find where the mods are, and delete them, i dont know the exct name of the folder, but it should take too long to look through them