Need an crash/error logger for the game

Context: I started working on a mod about 2 years ago, pretty huge scope, worked on it for about a year before I got busy with college and job. I kept the mod on the secondary for a year, and in the meantime I lost some files for it.

Problem: When I picked up the mod again this July, I've been experiencing regular crashes especially while entering interiors.

Need: I was wondering if there was an error log I could check, or a plugin that adds an error logger?

Version of game: Steam 2004 GOTY edition.