I couldn’t find any documentation on the roblox creator website about what the different levels are and what they change about the way error() does its job.
This command
EDIT:
If you see this, don’t be annoying. Instead of just liking the post and going away like most people do, ACTUALLY TRY TO ANSWER MY QUESTION THAT HAS BEEN UNANSWERED FOR AN ETERNITY.
Where Yolk was called. This level is default as well.
LEVEL: 3 → line 12
Where EggWhite was called.
LEVEL: 4 → line 15
Where Eggshell was called.
Any level beyond the script environment will result in a pure message (like with level 0).
P.S.: The profiles that like posts in series but have no activity are often bots or on some occasions newcomers. Also, #help-and-feedback:scripting-support better suits this question. Anyways, hopefully this helps!