Whats the reason and is it something bethesda can fix? I'm surprised no one has really brought this up since its such a big issue?

Quote from author of one of the most popular quest mods on the skyrim nexus which is Moonpath to Elsweyr

"This a mod conflict occuring with questmods.. probably deactivate a few and it should work again.

Edit: I'm beginning to think that it is something that the mod author has done wrong vs it being skyrim itself. Here are mods I'm using now that contain quest and all seem to work together without any of the problems stated in the OP.

http://skyrim.nexusmods.com/downloads/file.php?id=9782&navtag=file/images.php?id=9782&tab=3

http://skyrim.nexusmods.com/downloads/file.php?id=17289

http://skyrim.nexusmods.com/downloads/file.php?id=8333&navtag=file/images.php?id=8333&tab=3

http://skyrim.nexusmods.com/downloads/file.php?id=8429

http://skyrim.nexusmods.com/downloads/file.php?id=15678 (caused a crash by the fort that has been taken by black mages on the way back to whiterun from eldergleam sanctuary)

So everytime I install a mod with a quest in it I do hours of testing for stability purposes. So with these mods I seen no side effects. I'll test my luck and continue to add more to see what works and what doesnt. My testing consisted of fast travel, entering/exiting a cell, running from whiterun to Dawnstar on foot, Starting one of the quest lines. Everything was fine. I will periodically edit this post with more quest mods that work together as I add new ones. This is great news indeed and it seems like proof that some of these quest mods have something wrong with them.

Care to elaborate? I'm unaware of how quest mods don't work with other quest mods.

Ok Im pretty sure you have seen this problem before. I have moonpath loaded along with sea of ghost. There can be three things that happen

1:CTD One of the most common thing that occurs with users. They would play for a little and then a crash. Uninstall one of the queest mods and everything is flawless.

2: Objects will not load, for example alvors smithing shop was half gone. I've seen someone youtube walkthrough of sea of ghost where the ship is invisible but npc's are still on it.

3: You cant exit or enter a cell. If you try the game will go black screen and wont load or you get a crash.

I've not really heard any such issues, though I've never used quest mods yet. Can anyone else confirm? It would be extremely helpful to know of any such issues.

Yeah it's a pretty annoying issue with pretty much all the good-looking questmods I've seen. Even the 4 mods by the author who made Sea of Ghosts that was mentioned earlier don't play well together if you try to use all 4 at once or sometimes even just 2.

Nevermind.

I've had this as well with mods that add locations as well. I could never find a solution, so I guess I'll have to constantly remove and install other quest mods.

Is this an issue with mods that add new dungeons/houses and such? Maybe a navmesh issue?

I'm not sure what the state of the whole navmesh problem is right now.

4Skyrim

How much memory does your computer have? Can you check how much memory Skyrim is using when it crashes?

I used to get both occasional crashes outdoors and also meshes not fully loading (as you claimed with Alvor's shop) before the first large address patch came out a couple days after Skyrim release. At that time, Skyrim would always crash around 1.3 to 1.5 gig of memory used.

More recently, I am running about 70 mods, including increased spawn, skyrim live (adds a lot of NPC), and occupy skyrim (generates armies) plus tons of other stuff. Skyrim was always crashing around 2.6 gig of memory used which was happening a lot. The problem went away when I removed skyrim live and also removed occupy skyrim from the increased spawn patch, which got the memory down a lot.

The problem may not be quest mods but rather memory usage. High res textures may be part of it as they have to go through memory as well.

Hmm..I haven't seen any of these issues. As the previous posted stated, it may be a memory usage issue.

I doubt it is a memory issue, since even when I first launch skyrim in an affected cell the cell still refuses to load properly.

Doubt it's a memory issue aswell as I run meminfo and see my game is never loading more than 1800-2200mb. I have 12gb RAM, which shouldn't matter all that much though since game can only use 4gb anyways. Skyrim just seem to conflict in weird ways sometimes and we don't have any easy tools for troubleshooting yet as we did in Oblivion/Fallous

Are you referring to video ram or just ram? Either way I have 4gb of video memory and 12gb of ram. I have more than enough for skyrim. And as I stated it only happens when I have more than one quest mod installed at the same time. If I uninstall everything works fine no matter how much texture mods I have.

No from what I've seen its only quest mods, I have multiple house mods and moonpath installed and no problems.

No, this is entirely different issue. Problem with navmesh is that the 1st time you enter the cell everything is fine, but only the 1st time. After that NPCs just freeze, and nothing else works, not even your companion can follow you.

It has been my experience that Moonpath to Elseweyr tends to conflict with other quest mods. I had no problem running Quest-No Mercy, Vigilant of Stendarr Quests, Sea of Ghosts, Hall of the Dragon Priests plus one or two others at the same time.

I had problems with the four quest mods by the person that made Sea of Ghosts until I turned them into ESMs instead of ESPs, everything worked fine after that.

Turning esps into esms may cause large scale conflict issues down the road. Something to do with ONAM records.

ONAM records? Ooh boy even more problems I don't know about

What are those?

http://www.uesp.net/wiki/Tes5Mod:Mod_File_Format/SOPM

Could it be as simple as the mods in question editing some of the same records, causing one mod or the other to fail at certain times, depending on load order?

Struggled with this for a long time until I finally sat down and read this http://www.theengineeringguild.co.uk/index.php?option=com_content&view=article&id=371:skyrim-level-design-with-workarounds&catid=20&Itemid=115. Never did anything like this or even messed with mods, but I was desperate for a solution. The only way I've managed to bypass this problem is by making every single quest and dungeon I've downloaded an ESM+ESP combo. Never found a workaround aside from it, though I sometimes (very rarely) can use just an esp (The Dead Bee Scrolls is the only one off the top of my head). Wouldn't recommend ESM'ifying the mods straight-up because they're typically editing the vanilla worldspace, I keep all those references in the ESP.

My load order is pretty big now, but aside from the rare problematic mod leading to missing interiors in dungeons, scripts still function, the CK doesn't go berserk. If it is Moonpath causing the conflicts - any idea why that might be? I can't remember when I didn't use it, but I can definitely remember always experiencing an instant CTD at the main menu loading any dungeons (even ones that simply add an entrance in the Tamriel worldspace with no landscape edits). I haven't been able to test that extensively as I always start a new game when using a new mod/updating mods, but for the most part test different known problem dungeons whenever I introduce a new dungeon/quest such as Nightcaller Temple, Chillwind Depths, Snapleg Cave, random homes & village inns...

I did offer the Thirteenoranges fella one of my ESM+ESP's since I use all of his quests together, but he didn't seem to take to it. Overall the game just feels more stable, though this may be a placebo...I understand Arthmoor has warned against this type of structure as well! Was this a problem in Oblivion/FO3/FONV? I would love to just take an esp, clean it up and not need to do anything more, but like I said earlier it's VERY RARE that I could do that.

I have a problem with any quest or large area mod that causes a CTD on loading a saved game, or causes it to hang in the menu after starting a new game.

I don't know what either author has done with their files, but this sort of thing is the kind of thing one might expect with corrupted files that have been processed by TESVSnip. TESVSnip does not properly manage compressed records with subrecords that are also compressed. It simply ignores the compressed subrecords, thereby losing them entirely when a mod is saved with it.

CELL, LAND, NAVM, NAVI, and _NPC records are all known to have compressed subrecords. All of which are known to cause problems with corrupt entries.

Bottom line, one needs to find out if TESVSnip has ever been used on these mods in the past. If so, the authors have problems to correct, which may or may not be possible.

They're basically a list of overridden forms in an ESM. They tell the game which ones your ESM overrides in the parent files. Usually Skyrim.esm. They're a record type we have no reliable way to generate at present. The CK doesn't do this unless you work for Bethesda.

ONAM records are subrecords of the main TES4 header, so that link to UESP is pointing to the wrong type.

It's the big catch 22. Convert to ESM to fix navmeshes, break nearly everything else you've done in your mod. That's why the damn bug needs to get fixed. Folks with Twitter accounts may want to look into raising the issue there with the #navmeshbug tag. Keeping the issue in the forefront is the only way it's ever going to get fixed.

Has it been brought to his attention? I've always used TESVSNIP for cleaning UDRs and splitting these files, completely unaware of such a bug due to inexperience. This seems like a very major bug!