Telescope Errors are, well, just that! They are errors made by telescopes that cause an image to come back looking funny. There are a few kinds of telescope errors. Some make a stars light "bleed" and leak down to make it look like a comet. Some of them may look black or smeared. If your picture comes back like that, the identifier can't identify your photo, or the photos that others took of that object look way different, you may have gotten a telescope error.
Here are two examples of telescope errors:
Here are two examples of telescope errors: