Let that be a lesson to me to not go on a mod downloading spree... Does anyone know what causes this? Too many mods? Failed load order? Conflicts? Etc?

I'm currently using the latest SKSE, have 112 mods, Skyrim is up to date and am using an ENB though that didn't cause issues when I installed it. I've cleaned my saves with Save Tools, fixed all the dirty edits with TESVEdit, and still don't know what's wrong. Settings are in ultra, AA and Anisotropic are off, and in Windowed Mode.

Mod order: (Via the latest BOSS install. Will try TOOL to see if it's just a poor load order.)

Does the game launch at all, or does it immediately crash when you try? if it insta-crashes when launching you probably have a missing master file that one of your mods is dependent on. Check your mod documentation - I notice you don't have Dragonborn or Hearthfire installed. Make sure none of your mods require these DLC.

Did you add all of these mods at once after installing the ENB, or did you add them gradually and only started having the crashes after adding the last batch? If the latter is your case, disable that last batch of mods and try to play the game. If it plays, add the mods back in one or two at a time and play test the setup until it starts crashing again - that file will be your culprit. If the former is your case, you may end up having to do that with your entire load order.

WRT to your comment about the unrecognized plug-ins, yes they probably are in the wrong place and need to be manually placed in your load order.

I haven't played Skyrim in two or three months, but the last I heard, BOSS is no longer being supported with masterlist updates and the creators are telling people to switch to LOOT. I have no direct experience with it, but someone who does can help you out with it. This may solve your issue with the unrecognized plug-ins as well.

You cleaned your mods with TESVEdit - why didn't you create a merged patch for them as well? With that many mods it's pretty much essential.

ETA - one last thing. You say you cleaned your saves with Save Tools. The format and structure of TES save files is not well understood at all, and save cleaners often cause more problems than they actually fix. You shouldn't use them except as an absolute last resort with a completely borked save that can't be recovered or rolled back from.

Thank you both for answering!

Already checked, all the mods have their correct master files and those that don't were culled during the first round of DIY fixes I tried with me going back to double check at least once per each attempt to load the game. The game loads find and even gets to the start screen. It's when I select a save that it crashes a few seconds into the loading screen, though I have had three instances where it let me go through. It also tested it with all my mods turned off and just Skyrim, Update, Dawnguard, and the Unofficial patches installed and it worked fine. The load screen error extended to both New Game attempts and when I tried to load my old saves, though removing all the mods worked when I tried to make a new one.

I tend to install them in batches of five, generally when I'm browsing the Nexus after a session of playing, with the ENB being installed as a replacement to an older version I had left over from several months prior about a week ago. The latest batch was installed last night, and that's when the problems started. After I made the post I went through each mod I added that night and removed them, though it seems it still doesn't wish to work more than once. (I wanted to see if I could get a consistent response, but it only worked on the first try. Everything else crashed. (For the record I use NMM)

In regards to BOSS, also after the last post I did find and try LOOT, but that doesn't see to be much better - aside from recognizing all the plugins.

As for TESVEdit, as much as I hate to admit it I had no idea that was needed. I only started using it this week, as I stopped playing Skyrim for months and didn't bother with it before. ^^; Thank you for that suggestion, I'll do that this next time around. And thank you as well for the tip about the save cleaners, I won't use them then after all of this.

Because it isn't a problem with the base game (reinstalled it through steam as well just to be sure), would you recommend that I just uninstall all the mods and compile them back together one by one due to the problem persisting? Would that be the simplest solution?

Again, thank you both for the help. It's frustrating, but I realize that all of this is my own fault and I greatly appreciate all the advise and aid I can get.

What are the five mods that you installed last before you started getting these crashes? Some mods will "bake" scripts into your save files, and deleting them can cause a lot of problems. If you can provide a list, we can look it over and see if there are any problems.

Are BOSS or LOOT returning any warnings or error messages in their log files? If they are, please post those messages here.

Have you tried loading just your most recent save, or have you tried loading older saves and still get these crashes? If an older save will load normally, it's likely that your recent save has gotten corrupted somehow. I have also had balky saves that just won't load for one reason or another, and one trick that I've used quite a bit is to load an older save, get the game running with that save, and then try loading the newer save that wouldn't load before. This has actually worked for me a lot, and once I get the new save loaded I can save again, overwriting it, and then it behaves normally. Sometimes funny things happen with this game, and I can't guarantee this will work, but it's something you can try out if you want.

If this fails, and/or older saves also crash, try starting a brand new game with all of your mods enabled to see what happens. Play through the tutorial, leave Helgen, make a new save right outside and see if it will load.

But definitely consider using TESVEdit to create a merged patch for your game. It's actually quite easy to do, and it can definitely help with mod conflicts.