Game Crash: An unexpected issue occured. We're sorry for the inconvenence

Game Crash An unexpected issue has occurred.

I thought it would open and let me play without this error

It didn't open and automatically gave me this error

1. I would just open Minecraft Launcher,
2. Click the button that lets you choose your version,
3. Click 1.12.1 (download it if not already downloaded),
4. Click play,
5. And it will say "Game Crash: An unexpected error occurred. We're sorry for the inconvenience."