Creating and Installing Installing ESL mod files Guide:

ESL files have one major advantage over ESP files and that is that they do not contribute to the dreaded 255 limit for mods that the ESP files are subject to. They also have disadvantages such as they are limited to 4000 record id's, and can have issues with your load order. So choosing what mods to make ESL can be critical.

The best candidates for conversion to the ESL format is any single mod that uses only its own assets i.e. Armor Mods, or other stand-alone type mods that you don't have to worry about the load order overwriting other mod assets.

If you are going to convert a mod to ESL that you already have installed in a current game, be aware it is just like removing and reinstalling the mod, for armor or weapon mods this means you will need to reacquire the armor parts or the weapons. When you Load your save for the first time after activating a converted ESL, you will get the Missing modname.esp error.

Converting ESP to ESL

To convert an ESP mod to ESL just launch the Creation Kit, Loading Fallout4.esm and set the mod ESP to active. It is a good Idea to compact the ID's by going to File - Compact Active File Form IDs. then Click File - Convert Active File to Light Master. if the ESP still has too many ID's, it will generate an error and it will not create the ESL. That mod is too large to be converted to ESL. If you do not get an error the new ESL file will be in your Fallout 4\Data folder.

Activating Custom ESL files

There are two ways to Activate the ESL
1. You can manually edit the Users\Owner\Appdata\Local\Fallout 4\Plugins.txt and just change the *modname.esp  to *modname.esl  ( Note the " * " asterisk as Fallout 4.exe looks for this to know this mod is active also this file is set to Read-Only so you will need to set this to writable before you can edit it. )
2. If you are using NMM 0 63.17 you can just launch or reload NMM and the new ESL will be listed after any other ESL files you may have. just check the ESL version and uncheck the ESP version in the Load Order.


If you are installing a mod that comes with an optional ESL file, you will need to download and install the ESP version first to place all the
assets ( textures, meshes, etc ) then activate the ESL as noted above.

Update: Note that if you are manually editing your Plugins.txt file that the ESM and the CC ESL files will NOT be listed, as Fallout4.exe can
detect them as they are flagged as Masters.



Converting an ESL back to ESP

You can convert an ESL to ESP by loading the ESL up in the Creation Kit and then just save it and give it a new name with the ESP extension. I see the ESL as simply an optional replacement to the original ESP. If your upgrading a mod always do so with the ESP and once it is ready, create an ESL as an optional replacement file. But once the ESL is active in your Save Game File to go back to the ESP version, you need to do a clean save first ( Load the game without the ESL active and save it then load the game with the ESP active ) this will of course cause you to lose any items from that ESL and you will need to re-acquire them.



Some Additional Observations on ESL usage

So far I have only been converting small mods, such as my Caladons Boston Sky Home Mod and various Armor Mods. I currently have 17 active Custom ESL File Mods in my game. That is not counting the 3 that I have from the Creation Club. I also have 251 ESP mods. The new version of NMM will count the custom ESL files, ( my active plugins shows 268 right now lol ) but no longer disables mods after the 255 limit, So it is important to keep track of how many of each type you have as you still can't go past 255 ESP types without nasty things starting to happen.

Update: I have heard that ESL files actually use the 255 slot ( They use the FE Hex Slot ) in the ESP Load Order. So it may be a good Idea to limit your ESP enabled mods to 254 active. As I currently have 252 ESP mods Active I cannot yet confirm if pushing it to 255 will cause issues.

Update: It seems that ESLs are treated as Master Files and so can have ESPs slaved to them and can be Slaved to other ESM files, but ESLs themselves cannot be Slaved to ESP files. This means that mods that are dependent on other ESP mods ( i.e. Armor mods that require Armorsmith Extended ) are not good candidates for conversion to ESL. After further Testing, it appears I was wrong about ESLs slaved to ESPs as objir was successful in doing just that. Thanks objir for bringing this to my attention.



Where to get Nexus Mod Manager 0.63.17

If you don't already have the updated ESL compatible version of Nexus Mod Manager Version 0.63.17 you can get it here.

Nexus Mod Manager 0.63.17 with ESL Support


Known Issues with NMM 0.63.17:

For anyone who is having issues with adjusting the Load Order with Version 0.63.17 I am finding I have the same issue. if you have ANY Official Creation Club ESL files the New Version of NMM will no longer allow sorting of the Load Order. It is probably why they have not updated the main download for NMM. I actually have both versions installed ( just install this version to a new folder i.e. Nexus Mod Manager-63-17 ) with both versions configured to use the same mod storage folders. When I need to adjust Load Order of the ESP mods I load Ver. 0.63.14, once I have the Load Order of the ESP mods correct, (i.e. After running LOOT ), I Close NMM 63.14, then run this new version and disable the ESPs and enable the ESLs. I use this for adding new mods and ESL files and Launching the Game, as this one won't disable my ESL mods.


Credits : Thank You   MrMason  from the Nexus Forums for posting this update, it is MUCH appreciated!

Please Check out my other mods:

Caladons Mountain Retreat
NMM Transfer Settlements Blueprint Installer
Caladons Angel Aerie
Caladons Personal Portable Vault 88
Caladons Stonewall Starlight Citadel Blueprint
Caladons Starlight Movie Screen Lightbox Wall
Caladons Floating Castle Conquest Blueprint
Caladons Floating Castle Conquest Blueprint Mk 3
Lysandra Lovely LooksMenu Preset
Modding the Singing Settler A Guide to Custom Music and .Lip Animation
Jetpack Sound Replacer

Enjoy!