I'll just need some more clarification. Is it the Launcher that is crashing or are you having this issue with the launcher after the game itself crashes? Does the game run normally after Launcher end task? If you could explain in a bit more detail, that would be great! ^AM

Let's address the game crashes first. Try loading a different world to see if you still experience crashes to ensure no corruption. Double check antivirus/firewall to allow permissions for Minecraft, and ensure drivers are updated. Let us know if you're still having issues! ^AM