A few people who have downloaded my custom traits have been getting an error saying “Last Exception Caught with MCCC”. When I test these traits in my game they work fine and I dont get any errors from them so Im not sure what is causing them. Does anyone know why this is happening? I’m currently running the latest Jungle Update (Version 1.40.6.1020).

Same here. I would also want to know why.

There's no script portion to any of those traits, are there? I only tested Lucky/Unlucky myself (which is one that had feedback mentioning an LE). Without seeing the actual exception that is generated from their lastException.txt file and when that exception was generated (did it happen at game load, or when something else in game happened), it's pretty much impossible to say why this is occuring. The only things I can think of offhand would be that the user doesn't have their game fully patched, or they are running a script mod that is somehow incompatible with just your trait mods. The former seems far more likely to me, I can't think of any reason why another script mod would interfere with your traits - not to say that it's impossible, of course.

Is there any program that allows you to check for mod conflicts for The Sims 4? I know they had this for The Sims 3.

Not to my knowledge! I've asked the users getting the error if they can share their lastException.txt file for more info

You can get it on MTS! http://modthesims.info/d/561550

So someone has left a link to one on https://www.dropbox.com/s/4qa8zgn6m...Artist.txt?dl=0 and https://www.dropbox.com/s/fobmd0crl...eption.txt?dl=0, does anyone know why my traits are still giving out LE errors??

Wow, that's a toughie. There's a class reference error that is occuring which I have not seen before. Basically in a tuning reference somwhere, instance ID 'x' is being used where that instance is not allowed for that particular tuning.

The exception notes an instance ID of 139748, which is the piano_WriteLyrics crafting interaction. So either the tuning for that has been overriden by another mod and is referencing something it shouldn't be, OR a mod has a tuning that references piano_WriteLyrics in a place that it shouldn't.

For instance, something is expecting to find a reference to a 'trait' (just to throw out an example) and instead of the instance number of a trait, there is 139748 which is not a trait, and so bam that's invalid.

Or something is overriding the piano_WriteLyrics and somewhere in there it expects a reference to a "something" and instead finds a reference to a "something else".

Looking through the Python code it seems this may be linked to some kind of interaction lock out timer.

There is also some indication this could possibly be due to an invalid saved instance number for something (again, possibly a lock out although I didn't think those got saved) in a saved game. That could be due to something in the trait (or a conflicting mod) that is using a 64-bit instance ID (such as is used by a mod) where the save/load portion of the game is expecting a 32-bit value (such as used by EA's XML). There were several of these errors in the game, and although many have been found and corrected, I'm sure some still exist. But those typically will throw an error as the game is saved that the number is invalid and the game save has failed.

Sorry if this is so vague. It's tough to figure out, particularly since neither you nor I see this error getting thrown. Until I can get pointed to a "this specific one" of your traits is causing this exception, download a copy of it, put it in my game and see that error occuring myself, figuring it out is largely a matter of semi-blind guesswork.

ETA: I noticed another thread (https://modthesims.info/showthread.php?t=608369) on the help forum that references this and has another LE. The referenced instance ID on this thread is another one, not the piano one, so... yeah, that doesn't really help, but it's definitely not something you're doing with the piano_WriteLyrics tuning!

icemunmun posted a possible solution in that help request thread - see https://modthesims.info/showthread.php?t=608369 to see if this helps at all.

The problem thats causing those errors is with WickedWhims 3.2.4.122h. In other words, a mod they have installed called wicked whims. It is possible your trait is conflicting with something in the wicked whims mod. Ask them to remove wicked whims and run a fresh game with fresh sim and town and your trait. I doubt the error will reoccur. Why your trait is conflicting with Wicked Whims though, I dont know. Wicked whims is a big mod.

How do I get it to show up in Python? I don't normally use it so I'm not sure The trait uses 139819 which is the Write Lyrics (singingSkill_startsWriting_Piano), do you think this could be related to the piano_WriteLyrics tuning error? Thanks for the link too! Hopefully I can get this sorted!



I removed all mods except for my traits and installed WhickedWhims and instantly got a Last Exception error, I've attached the file. Some people using my traits who are getting the error are using WhickedWhims and MCCC so I think something in the files must be causing the conflict.

Mccc isn’t conflicting with your trait, if so there would be reference to mc_tuner or such like. Wicked whims and your trait may be sharing an instance key or the interaction is being used in a similar way to yours, not sure as I’ve never used wicked whims or looked at it’s file.

Alternatively, wicked whims may need an update after my first pet patch?

I’m also going to check mod constructor V3 as I made another trait last night and got a last exception but I’m quite experienced at making traits now using it and it was relatively small in comparison to my Aphrodite and Dionysus traits, nothing was different so it may also be possible that since the patch, the way mod constructor is exporting statistic based buffs is corrupted.

Ah I see! I haven't tested with MCCC but someone who didn't share the LE.txt file said that it caused one! At least I know what to look out for now And possibly! I think WW was updated quite recently so I think they must be sharing an instance key like you said.


Let me know what you find! Hopefully V3 may be updated soon if it is!

Users typically think that when MCCC displays an exception notificaiton that means that MCCC caused that exception, which is in my experience very rarely the case.

Well my fellow creator, I tested my trait that was throwing the error again, opened up the last exception file and have a guess what xml file is throwing the error? Yup, Piano_WriteLyrics! I don't use wicked whims, I do use MCCC which is mentioned in the exception file, however the other craftingstepinteractions in the trait do not throw errors, therefore I am assuming that particular tuning file has a bug. Not your fault. Just remove the buff for it from your trait and it should stop throwing error.

Ah thank you so much! I’ll try that!!

Thanks to a player who replied to the thread in the help forum I was finally able to get one of the mods that cause the LE and was able to track down the precise cause of those errors.

The issue is that in the list of affordances within a user_running_interaction test, all of the affordances must be based off the SuperInteraction class. Mixers, and several other types of affordances, are not based on super interactions and so they will produce this error as they are loaded. Even though these are not generating LE errors in your or my game those values do get thrown out of the list so there is no point in including them.

An example of one of these would be the inclusion of the affordance 136725 (Toilet_Talking_soc_mixer_Friendly_tellJoke) in the user_running_interactions tests of the good sense of humor trait's loot action.

You may find the attached script mod useful as, like mine, your game is not logging those to your last exception file. This will create a _load_etree_node_errors.log file in the same folder the mod is placed in. It will take a few seconds after the game reaches the main intro screen before all those nodes are processed and the log file gets generated.