errorIndicatorSymbol

val errorIndicatorSymbol: String

Despite, what, a hundred thousand employees(?), Microsoft seems unable to support the simplest things in Windows. Like including a font that has a significant portion of Unicode supported, or devising (or even copying!) a mechanism to substitute glyphs from fonts that do have those code points. So if you're doomed to be on Windows you'll get an inferior right arrow with hook to indicate the location of errors.

That will teach you.