@Crdroxxpl There are mod related and not mod related LEs. A lot of times if the culprit is a mod, it will be listed in the LE itself. So you can search for clues in there.
Otherwise it's just a lot of hive knowledge. They aren't easy to read but if you practice, you'll start noticing patterns on which LEs are the same as others posted around the internet.
There's also this webseite.
https://lastexception.com that can help you but I don't use it much and don't know if it's kept uptodate or what the mechanism behind it are.
You can always ask for help with your LEs here but if you use mods that are 18+ or something very questionable there might not be an answer. Same goes for pirated content.