The hopper crash tracker behaves incorrectly if the server brand is null when the crash occurs (IE, the game crashes before the MC|Brand packet is received but after the player joins the game).

When the brand is null, a NullPointerException is caught and handled, and the brand is treated as ~~ERROR~~ NullPointerException: null. Hopper seems to be detecting that the brand is not vanilla and thus treating the server as modded, even when it isn't.

A demo of this: MCX-3002118/77338978 says:

	Server brand: ~~ERROR~~ NullPointerException: null
	Server type: Integrated singleplayer server
...
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)

Given that the client is (most likely) unmodified, and that it's an integrated single player server, the server brand should be vanilla, but is null. Why it's null is beyond the scope of this issue, but hopper shouldn't be assuming it's modded just because it's null. While there are some modded servers that don't send a brand, it can also happen in vanilla and thus the brand being null shouldn't be used to mark an issue as modded-only.