https://imgur.com/a/Y1tdhpX

is it possible to be incompatibility with a mod? to my knowledge im not using any mods that modify train behavior

It looks like it's related to the items inside the wagon, could you send me the save file of that happening so I can see?

im trying it out in a world editor, hmm, im using https://mods.factorio.com/mod/EditorExtensions this mod as well, and i just filled the wagon with stuff i had in inventory (so mostly modded EE stuff) ill try again with vanilla items with character, and see what happenś, if it still crashes ill send my save file, thanks!

So, after testing, its still doing when using vanilla items, here is the save file:
https://www.mediafire.com/file/soja95ivufkfwde/Renai_Transportation_Venomless_Save.zip/file

So I took a look at your save and the code and honestly my coding sucks so bad that I can't tell at all what the problem is 😅. I'm just gonna try and rewrite that section better, like tearing down an old spaghetti green science setup to rebuild it with some actual structure

Nevermind I figured it out lol, you can try it on the new version 2.0.4

oh nice! will try