The latest snapshot for 1.13 17w50a keeps crashing

Every time I start the new snapshot (17w50a) for 1.13 it keeps getting me back to launcher and saying,"The game crashed whilst initializing game
Error: com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Invalid escape sequence at line 4 column 37 path $.pack.description".