Can't run Minecraft snapshot 18w01a

When i try to open minecraft 18w01a, it opens the loading screen for a sec and then it crashes. The crash error is this one:

The game crashed whilst initializing game
Error: com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Unterminated object at line 4 column 59 path $.pack.description

The minecraft game output is this one (without showing the debug part):

4030 debugs7 infos
18:14:43 launcher Preparing to launch minecraft client for 18w01a
18:14:44 launcher Checking installations.
18:14:44 launcher Minecraft client 18w01a is ready to start.
18:14:44 launcher Starting!
18:14:44 launcher Using default game log configuration client-1.12.xml (outputs XML)
18:14:46 bnv Setting user: Casiel368
18:14:48 bnv LWJGL Version: 3.1.2 build 29

I'm not using any texturepacks or mods or anything, just vanilla. As i've tried running without any other programs working at the same time. I've disabled the texturepack i normally use from minecraft 1.12 client and the snapshot still not works.