Can't access some parts of zones because of "critical error"

I was levelling a char in mulgore, but kept getting crashes in specific areas coz of a critical error, but it just says that i cannot load an asset, namely "KL_TANARIS_GOBLINBLD_C.WMO." so i cant get back to my char coz of this crash loop.

Try using the character unstuck on the website, which will teleport you to your hearthstone location. also, you should redownload the client.