You CANNOT Remove Mods Mid-Playthrough

[smr1957]

(Initially posted in original Skyrim forum)
Am posting this because the problem of individuals removing mods mid-playthrough and subsequently having problems seems to be cropping up quite a bit recently.

(PURE MESH/TEXTURE REPLACEMENT MODS ARE SAFE TO REMOVE. SO ARE MODS USING VANILLA ASSETS AND SPAWNS.)

From Arthmoor:
"3. There is no such thing as a clean save. It does not matter who tells you there is, it doesn't exist in Skyrim. You cannot remove any mod, not even the patch, without there being some data that's been permanently changed. Doing this repeatedly WILL damage your save and WILL eventually lead to it becoming corrupt and unusable. Bethesda's own developers have confirmed the only way to properly remove a mod is to load a save made BEFORE that mod was introduced into the game. If you started a new game with 10 mods installed, you're going to be stuck with those 10 forever."


Unofficial Skyrim Legendary Edition Patch by Unofficial Patch Project Team - https://www.nexusmods.com/skyrim/mods/71214/?
Posts section, second stickied post, point of information #3
posted @ 2:08, 8 Feb 2016 , stickied at 2:08, 8 Feb 2016

and Ilja:

"You can't remove mods from ongoing game. Skyrim bakes script data to save file. There is no such thing as a clean save, when mod is removed. "Clean save" is for mod updates only. This includes work done with Save Script Cleaner. That tool cleans obsolete entries and orphaned scripts from the game, but script data will remain in the save file, causing Papryus to constantly check it and creating errors.

If you removed scripted mods from ongoing game, then you will have to start a new game." - Ilja

https://steamcommunity.com/app/72850/discussions/0/343788552537617802/#c343788552538346202

Also:
https://steamcommunity.com/app/72850/discussions/0/365163686057140233/?tscn=1504123538#c365163686058904424

And, again from Ilja:

"I believe that misunderstanding here is that people can not make a difference between closing active scripts from the game world and wiping Papyrus script data from Papyrus. Latter is impossible to make in a clean way."
https://steamcommunity.com/app/72850/discussions/0/1495615865205745360/?tscn=1529568370#c1696043263497229374

"You can't uninstall most mods from ongoing game. Skyrim bakes script data to save files and unisntalling the mod does not remove it. It only causes errors in Papyrus scripting system.

Even if mod does not use any scripts, it's changes would need to be subjects of Skyrim vanilla respawn/refresh system." - Ilja

https://steamcommunity.com/app/72850/discussions/0/1368380934258855911/#c1368380934263549103

furthermore:
"It is important to note that Skyrim does not have method to remove mods from the game. It bakes script data to save files and can not retroactively update scripts from the game.

This means that Papyrus will keep checking after scripts that were removed from the game, causing errors, slowing down and eventually breaking.

You should test all changes with a new game. Once you are done, then you will need to start a new game.

You can always safely remove mods that use:
- Vanilla spawn points and assets, without direct world edits.
- Pure mesh and texture replacement mods.
- World edits subject to vanilla area respawn system.

Otherwise removing any mods will leave the data baked in to save files. That will cause issues in the game, starting from oddities and potentially ending in completely wrecked Papyrus for the character you were playing." - Ilja
https://steamcommunity.com/app/72850/discussions/0/1470841715944914155/?tscn=1502534549#c1470841715968830878

from Nazenn:
"Cleaning out a mods referances does not make that mod safe for uninstallation. Cleaning your save file regularly won't stop save bloat or other script based errors. :)"
https://steamcommunity.com/app/72850/discussions/0/523890681422555089/?ctp=5#c481115363852020188

There is also this, by Altbert:

"If you want any proof about the tons of "if's" just take a closer look at the Save File Format described here:
https://en.uesp.net/wiki/Skyrim_Mod:Save_File_Format#Plugin_Info
All possible info on plugins (ESP and ESL) files is stored in the save file by name, and everyting in it by ID, including scripts, base and referenced NPCs, and every other possible object, already present in the base game, and added or changed by a plugin, even if it only changes one game setting or if it is only used as a dummy to load a BSA file with only meshes and textures.

Every object in the game has a Reference ID, stored in the save file. This ID not only points to an ingame object, but also points to the plugin that has changed or added that object. This will also include MCM scripts. Not sure about .NET DLLs (yet, but hope to find out).

As mentioned before: DO NOT UNINSTALL PLUGINS MID PLAYTHROUGH!"
https://steamcommunity.com/app/489830/discussions/0/3037102935221914007/#c3037102935223556762


WHAT GETS BAKED INTO A SAVE

Again, from Arthmoor: [Skyrim] Information Baked Into Saves - https://www.afkmods.com/index.php?/topic/3676-skyrim-information-baked-into-saves/
(reading the above linked full discussion is highly recommended)

"So I figured it's about time to begin keeping track of what does and doesn't bake itself into your saved game. Enough things do so that it's getting hard to keep track of in my head, and what good does it to anyone else up there... where my fingers are too short to get it out....

So far, we have:

- Papyrus script properties. These become permanently baked in from the moment the game starts and/or when a new mod with scripts is added. Script properties can only be updated by forcing them to change via an update script, like what the USKP uses for retroactive fixes.
- Objects pointed to by Papyrus properties. These can never be moved, even with scripted commands. This data is baked in from the moment the game starts and/or a new mod is added. Most attempts will simply fail silently, while others will log an error saying the objects can't be moved.
- Objects pointed to in forced reference aliases for quests. These are not supposed to become permanently persistent, but more often than not that's exactly what happens.
- Changes to any vanilla objects made via scripts. Including global variables and any other information. These changes are written as modification records in the save and can only be reversed with another script.
- Map Marker data. Specifically, if you alter a map marker, remove the name from it, then proceed to play, the map marker will permanently lose this information even after the mod is removed.
- Positions of havok enabled items in cells you've visited. Even if you move them in the CK and you haven't disturbed them yourself. This may reset itself upon the cell's next cycle, but so far all indications are that it won't.
- Positions of moveable static objects become permanent after your first encounter with them. Prior to this they will update.
- Changing ownership on a bed from nobody to a faction does not appear to update, while changing it from nobody to a specific NPC appears to work fine.
- Several fields on NPCs are known to bake in: Crime Faction, Faction memberships, Inventory items, Morality (AI Data tab), the opposite gender animations flag. These fields appear to only bake in if the NPC actually loads into memory at least once during play.
- Facegen Data for NPCs. This seems somewhat hit or miss, but more often than not, if you have encountered an NPC while playing, any changes to their facegen data that may be made later will be ignored.
- Timescale changes. You can make a one-time change to the game's timescale through an ESP, but after that, any changes to timescale must be done either via Papyrus or the console as the change is permanent in the save once made."

"All Papyrus scripts get embedded into the save from the moment you install a new mod. No exceptions."

"I don't know where you're getting the message that we can clean saves. We can't. Those stop scripts cannot resolve the issue. They only serve to shut down the running update loops those mods have. They cannot reverse the actual changes made."

[re: Cleaners] "anything ... claiming to edit ANYTHING in the save game - the format hasn't been decoded enough for any of these utilities to actually work as advertised. They should have been removed from Nexus considering they're dangerous and will only corrupt your save further.
The only solution to the baked data problem is to abandon the save and start a new game."

[Re removing and then reinstalling] "The save still remembers the old form ID and never gets rid of it. You can come back months later, change your form ID back to the old one, and it will simply resume using the old data in whatever state it was last in. As far as the game is concerned you've got a pair of quests using different instantiations of the same scripts.
This is not something that happens when changing a form ID on some other object like a rock or a tree or whatever. Then again, changing a form ID on something like a quest was never designed to be possible."


And in layman's terms:
"think of modding a game as painting a picture, you can add as many mods as you want as you go along, when you decide to remove one exspecialy one that has been running for a while you have layers upon layers of script that became dependant on said mod and will cause issues with your current playthrough, from as simple as a missing set of stairs to the game crashing, it's best if you just scrap the current save and start over if your going to remove mods." - AriekB
https://steamcommunity.com/app/72850/discussions/0/1483232961043102614/?tscn=1508126851#c1483232961044934449

Your options are:
1) continue with the mod in place (NOT an option if the mod is actively breaking or bugging the game)
2) load a save made before the removed mod was installed
3) start a new game


You may also need to refer to the following:
How to verify integrity of game cache by Ilja -
https://steamcommunity.com/app/489830/discussions/0/1843493219431033688/

And:
https://steamcommunity.com/sharedfiles/filedetails/?id=2743619856

For those who prefer a vid, see this by GamerPoets - Clean Installation Tutorial
https://www.youtube.com/watch?v=zQ5uNCKOKmI


And, as always, make sure you thoroughly read the pinned topic and do as it says:
Skyrim SE: Guides and Resources by Ilja
https://steamcommunity.com/app/489830/discussions/0/340412122413706606/
VERY IMPORTANT if you wish to successfully mod your game


And if new to modding the game, read the following to see just what modding Skyrim entails:
Excellent advice regarding modding Skyrim (essay written by PeggleFrank for original Skyrim, but in general applies to SSE, as well) https://steamcommunity.com/app/72850/discussions/0/343787920127409994/#c343787920127583150

And if you don't want to go through all the bother of researching mods yourself, and then trying to get them to work in your game, I strongly recommend the following excellent guides (constantly updated and maintained by Vlad 254, one of the forum's most respected members and currently the best guide author around).
For the most basic and minimal mod build, see this guide first:
https://steamcommunity.com/sharedfiles/filedetails/?id=2738338974
For a more complex beginning build, there is this:
https://steamcommunity.com/sharedfiles/filedetails/?id=2636368499
and it's associated thread:
https://steamcommunity.com/app/489830/discussions/0/4676423350587480430/


DETERMINING WHAT MODS ARE PRESENT/MISSING FROM A SAVE

Sometimes, you may have a save but don't know what mods were installed when that save was made.

Use Wrye Bash https://www.nexusmods.com/skyrimspecialedition/mods/6837/? to find out which mods may be missing from your load order. If you want to discover what mods you had active in a given save, all you do is click on the tab that says Saves. In the left hand pane, you will see a list of your save files; clicking on any of those save files will show - in the the right hand center pane - a list of all your mods that were active for that save.

Blue checkbox indicates that all mods are present and in exactly the same order as they were for that save.

Green checkbox indicates that all mods are present, but not in precisely the same position (mods have been added and are in between the mods present in the save (not an issue, and can be considered as good as blue)

Orange checkbox indicates that some mods are in a different position then they were in the save (due to resorting the load order) - not necessarily a problem as the game will handle this automatically, but due to the load order being modified, you may see some changes in game (as a mod overwrites another that it originally did not).

Red checkbox indicates that the highlighted mod is not present in your load order. This needs to be corrected by reinstalling that mod, as you cannot remove mods mid playthrough. If you cannot or do not wish to use that mod anymore, you must go back to a save from before it was installed, or start a new game.

[smr1957]

What I did in my game, because I was beginning to see a very, very, slight lag due to the number of mods I had installed, was to reduce the FPS cap to 30 - just so the game would have a little more time to process all of the necessary data.

Of course, the more items and the larger the number of things, the greater the amount of items that the game has to process and remember, so I try to keep things to a minimum. Sometimes difficult to do given the number of mods that effect what items are listed or with the number of items that you may have stored.

And, of course it also depends upon your machine's specs, as well.

[Iceira]

well i can only give feedback, and thats why i mention this to you , main game is have been access all over skyrim was not a problem ( sure i have many items on me with 21000 weight/25000, but whatever this is i dont know i have been up at 40000 with np, until i did heartfire and dawnguard, ( ofc its logical more area more data it need to keep track off )

and thats why i try tell you this, was not a problem with no mods playthrogh, but to suspect something is not proof, i can only try later get another MCM menu enabler and then try remove skyui. but there is a long way to end game now. ( unless you want a copy of the game and see if you got same issue , but thats more a confirm yeap, not sure i have seen comunity doing faulty finding that way. ( i have to look into MCM menu as odrim once had , and see if i can skip skyui. and bypass testing not other mod issue. ) thats the prize we pay with mods.

[smr1957]

All information and feedback is good to have, Iceira, though I have often noticed that things seem to vary from one player to another player. Why this is, I don't know - maybe just the way the game is, or an individual's machine? I know, that in reading things in the forum, I come across problems that experienced people have with their game, yet which I have never encountered. And it cannot just be explained away as "well, they did something wrong" as it can with people who may have considerably less experience. Just one of those things - everyone's experience with the game is different, and sometimes there is no adequate explanation for it.

But, as always, the more information we have, the better the chances of understanding things.

[smr1957]

Just popping this to the top so that people are reminded about the detrimental effect of removing mods - have seen a number of posts lately where people are having issues, and when asked, state that they had removed mods mid-playthrough,

[Humpenstilzchen]

Thanks for the info I won´t remove any mods midgame anymore.

[smr1957]

Originally posted by Namenloser Held:

Thanks for the info I won´t remove any mods midgame anymore.

It's a common mistake that people make - and even some mod authors, as well!

[Explorerbeyondthemap]

Thanks to all who contributed to this post. This is such valuable information! I finally learned how to troubleshoot the mods the proper way so that I don't end up with an unplayable game and mods that I'm stuck with.

I found that just spending a little time to learn about the mods I'm downloading, as well as looking at gamer reviews of the mod, and finally paying close attention to the instructions provided by the creator of the mod regarding load order, compatibility with other mods, etc.

It's worth taking the time to get a good set of mods to work together so that you can play a game you can rely on not to crash, etc.

I've also found in my experience that 20-30 is indeed about the right amount to use at any one time (at least with my skill level in troubleshooting and research). I think it's better to have a smaller amount of quality mods rather than try to saturate the game with a hundred mods. Not saying that can't work, but I find it be overwhelming to try to manage more than 20-30.

The way I think of it is, you're kind of building a personalized world to roam around in, and once you've committed to a set of mods you are committing to that "version" of the world if that makes sense.

I've also found that the game runs much better if you don't try to add mods in the middle of a playthrough. I know there are varying opinions about that, but I've found that sometimes adding mods can cause issues. Not always but enough to make it notable.

Thanks again everybody, this is great info!

[Vlad 254]

@Gamer, this is great to read. Modding is reading and it looks as if you've not only come to that understanding but have done just that. Modding is also staying within your limitations and again it looks as if you understand that. Not removing most mods mid-playthrough can't be stressed enough. There are a few that can be like textures for example but not removing any until you get a better understanding of the very few categories you can I'd always suggest just don't.

[smr1957]

Am glad that this is found to be useful, and can only wish, that as Vlad said, more people would understand (as you do, Gamer) that to mod the game right, it involves a lot of reading.

But, don't think that because you read this and now know the info it contains that this post is no longer of use! No, because if you ever find you can't sleep, you can read this again and there is a good chance it will put you to sleep - LOL!

Anyway, in all seriousness, people should be not only reading this, they should be reading or at the very least, referring to, the pinned topics - they are pinned for a reason, not just to take up space at the top of the forum.

[Putt]

You thought it was a good idea to remove mods mid playthrough...LOL

[smr1957]

Have seen a number of topics lately where people had problems directly caused by removing mods mid-playthrough - remember, but for the exceptions listed at the very beginning of the topic post - YOU CANNOT! No ifs, ands, or buts about it!

Also, since it is sale time and a lot of new people are about, they should at least take a look at this guide before starting to mod their game:
https://steamcommunity.com/sharedfiles/filedetails/?id=1986067552

[smr1957]

People REALLY need to read this. Since I made my post here earlier this morning, and thus moved the topic up, another person borked their game and will now probably have to restart if they do not have a save to roll back to (and from what they posted, they do not).

Please take this to heart - I hate to see people breaking their saves and maybe having to completely restart the game because they did not see and read this most basic of all information.

[Wooden Ladle]

Out of experience, I disagree. In my super long (lvl ~80) LE playthrough which is even more unstable than SE, I had uninstalled tens of mods (with and without esps and scripts), even replaced some with mods that have effects on same/similar things. My biggest problem was inconsistently crashing in the wilds at most every hour, which is totally fine if you just quicksave time to time. Just make sure you don't uninstall big mods that change a lot of things unless the author says it's safe, don't uninstall mods if the author says not to, and always check the mod page's uninstallation instructions.

You're modding, there WILL be bugs and instabilities. You WILL have to google your problems, use the console, make changes to files and inis, use programs like xEdit and MatorSmash and so on. Just be responsible, only get heavy mods you know you won't uninstall, look for alternatives that are lighter etc.

A little extra advice, some mods just let you disable it in their MCM so you may not have to uninstall them. Also cleaning your save game is still meaningful even if it doesn't guarantee a clean game.
For example, I learned about Classic Lichdom, an extension for the classic mod Undeath, but I'm not getting it right now. Because I already have Undeath - The Ascension (another extension) which is an old mod that is made for an even older mod, and it's not being currently updated. These mean it's very likely that stuff will break if I uninstall it to replace with another.

[SpeedFreak1972]

Err some saves won't even LOAD if you pull certain mods .... and yes I've been there. Also most of us have very large load outs I mean I work atm on a load order with over 800 mods smr's load order goes well beyond the 1000 mods. People who know a lot about how the game engine works also say you can't pull or disable mods

[Ilja]

Because the script information is not being cleared from the save file.

Not every script causes immediate problem. Some may remain dormant in save file through the whole game play.

But if Papyrus find any condition to check the script, then the script is not there. That will cause Papryus to create errors and has good change to break it down.

Few clarifications to this.

Game doesn't know what is official file and what is a mod file. It only knows main file. Everything, including DLCs, are basically mods for it. So are all the plugins you toss in. It treats all files as they were actually in the main game, meaning that any script lost from removed mod equals as if it was shot away from the main file.

Game deals scripts within frame. If it can not complete the script within time limit, then that script is pushed in to next frame. If that script errors, then it is not cleared. Multiply errors will take the time within frame from other functions and potentially pile up. Game doesn't drop these scripts. It attempts to run them within session, until it succeeds or runs out of memory and crashes to desktop. If any script is called by the save file, then Papyrus VM will attempt to persistently complete it.