[ Player ] ...Your mod causes a CTD when I enter this vanilla location

[ Mod Dev ] ...I never touched that area so it has to be some other mod or combination of mods.

If you have ever seen this recurring theme in mod forums then read on.

Short Story
I found a recurring error in the script logs that was caught in an endless OnUpdate() trying to assign a variable that didn't exist. What caught my attention was that this was a vanilla script attached to a vanilla object that was used in a mod I was running. The script was set to update every 0.25 seconds so you can imagine how much time was taken by the script engine. I kinda have a habit of paying attention to the script logs. Since I wanted to clean up the log I took a look at the object in the CK and found that it was also used in the vanilla game but only in one location. A Dwarven ruin. So I thought maybe I'll go run though the quest and see what happens. I got an immediate CTD when entering the ruin. So I went back to the mod added objects and disabled them ingame. Then went back to the ruin and could enter without an issue. I was able to reproduce this with 100% success over and over. Under normal troubleshooting the player would swear that this mod caused a CTD and the Mod Dev would think "Why would it".

When I ran though the ruin with logging enabled I didnt get even one error for this object. So why would it cause a catastrophic error when added with a mod and not when used in the vanilla game? It seems that gamesas maybe worked that out over lunch and forgot to invite all the potential mod devs to attend. Every object in the vanilla game has been tested for it's use in the paticular instance that it was used. Every situation requires debugging.

The Moral of the Story:

Make sure that vanilla objects are traced back through to see how it was used in the vanilla game.

Troubleshoot problems with the error log and ensure that every object with a script "whether it be a vanilla script or not" isn't in an error causing loop.

Better still...if a script is using the onUpdate() function create a copy script and give it a new name and use that one instead so there is only one instance of it in the game and it won't conflict with vanilla locations that might be also using that script. I just tested this with the mod descibed above and didn't get a CTD when entering the vanilla ruin. Tried twice. I created a new script that was identical in every way to the vanilla script except for it's name. Set the properties exactly the same. It continued producing the errors but didn't CTD. The script engine was able to separate the two and keep humming along.

I'm not saying this will happen with every object in the game as many of them need to interact with the game on an ongoing basis but it certainly applies to static animated objects.


From the guy who will propably never finish the mod he is working on.

If this has been talked about over and over and I missed it then I guess it's a wasted thread. Apologies

Regards

Thanks for this. I've had people report similar issues with a couple of my mods, I'll check on all the objects I use.

Another thing I've discovered is that Steam Workshop in particular sometimes provides a corrupted copy of the mod, so that the game just crashes on the load screen with no other feedback. The only fix was the delete the BSA and ESP and have Steam re-download the mod. This has been reported to me at least a couple dozen times, and my mods aren't even particularly high-volume.