Loading Multiple Master/Plugin Files
If you want to create mods with multiple master (.esm) or plugin (.esp) files loaded at once, you have to make some changes to your SkyrimEditor.ini file located in C:\Program Files (x86)\Steam\SteamApps\common\Skyrim. You can either download the file below and replace yours, or you can make the necessary changes yourself as seen here:
[General] bAllowMultipleMasterFiles=1 bAllowMultipleMasterLoads=1 [Archive] bInvalidateOlderFiles=1 SArchiveList=Skyrim - Textures.bsa, Skyrim - Meshes.bsa, Skyrim - Animations.bsa, Skyrim - Voices.bsa, Skyrim - Interface.bsa, Skyrim - Misc.bsa, Skyrim - Sounds.bsa, Skyrim - VoicesExtra.bsa, Skyrim - Shaders.bsa, Update.bsa, Dawnguard.bsa, Dragonborn.bsa SInvalidationFile=ArchiveInvalidation.txt iRetainFilenameOffsetTable=1 iRetainFilenameStringTable=1 iRetainDirectoryStringTable=1 bCheckRuntimeCollisions=0 bUseArchives=1 SResourceArchiveList=Skyrim - Textures.bsa, Skyrim - Meshes.bsa, Skyrim - Animations.bsa, Skyrim - Voices.bsa, Skyrim - Interface.bsa, Skyrim - Misc.bsa, Skyrim - Sounds.bsa, Skyrim - VoicesExtra.bsa, Dawnguard.bsa, Dragonborn.bsa SResourceArchiveList2=Skyrim - Shaders.bsa, Update.bsa, Dawnguard.bsa, HearthFires.bsa, Dragonborn.bsa
Exteriors Not Loading
If the exterior of your build isn't showing up in the Skyrim world space, you can follow these simple steps to get it to load.
Find the exterior of your dungeon and double click (right click-edit) on all the large objects of your build’s exterior.
In the bottom of the Reference Window check the "Is Full LOD" box for each object and save your file.
After saving, uncheck "Is Full LOD" on the exterior objects and save your file again.
You do not need to save after every exterior piece. Only once after they are all checked, and once after they are all unchecked. This does not apply to areas which you’ve generated/regenerated the LOD for.
NPCs/Followers Not Entering Cells
After navmeshing your dungeon, you have to finalize the navmesh to allow NPCs (such as followers) to pass through load doors and enter different cells. In each interior cell, make sure you are not selected on anything and then click the finalize navmesh check mark on the navmesh toolbar (pictured below). In the exterior cell connecting to your interiors, be sure to do the same thing. Also finalize the navmesh in exterior cells you create or change the navmesh in (navmesh along the cell border should line up with the navmesh of the next cell). After finalizing correctly, you will see the navmesh triangles that have the door markers on them turn green, as well as the navmesh borders along the cell.