Sometimes when you're playing a Quest adventure, a script or function will throw an error message, like invalid object/attribute, out but otherwise keep going.

I'd love to fix all errors, and I try to. But I think in some cases for a complex adventure it may be hard to find the root cause, or it doesn't really hurt anything. Yet seeing errors is an immersion-break for the player.

Is there a way to make Quest not display errors during play at all, so players have a cleaner experience?

just note that, unless you inform them in another way (such as on your blog/webpage and/or in-game via a 'msg' Script at the beginning of the game), they're going to be assuming that the game feature(s) works, when it doesn't, and then be baffled/upset when they finally realize that something is wrong with that game feature/s (which indeed is actually not working).

I definately understand that it breaks immersion, but the error messages are there to let you know something's wrong in your code and you need to fix it up and to let the people playing know as well.

The best thing to do, is to fix up the error(s), and indeed, depending on your game complexity and/or organization/coding ability, it can be hard to find the sources of the error(s), but you can always post/pm your game code to people who know coding well and who you can trust, who can/will find and fix the error(s) for you.

unfortunately, I don't know how to turn off the error messages, but there's definately a way to do so, as error messages are coded into quest, so they can be -uncoded from quest, or better is if quest has coding for being able to toggle the error messaging (on/off), which probably quest does.

someone else who knows quest's built-in code can probably help you with finding quest's coding for the error messages and turning them off, but again, I'd recommend just getting the errors fixed, as that the best thing to do: just don't have any errors, have a perfect/flawless/error-bug-free game.

I will do as you say if there's no other choice. I'm referring mostly to false positives. That the game is doing exactly what I want it to, but it's throwing errors anyway. It's a decision between "Do exactly what I want but throw errors" or "Take a less desirable alternative but throw 0 errors". I'll take the zero errors any day, because it's sloppy to show that to the user.

I have also seen other open-ended/sandbox Quest games throw errors, and I don't know if their scripts are working as they intend or not because it doesn't obviously break anything or stop progress. My own game is in an early stage, but I wonder if I'll have the same situation as them, despite my best intents and efforts.

False positives? can you give some examples? I didn't know quest could do false positives, always thought if you got an error, you had something wrong with your code and/or game functionality/feature/mechanic/etc.

Too bad Quest has is poor debugger...
One way to track down a suspected error, if to print messages in your code in an area you are checking.
(gota take them out after tho!)
Then when an error pops up, hopefully, you have a message close by that will give you a clue as to what is happening.