My game keeps doing this every time i try and play. I've tried uninstalling and deleting my .minecraft folder. HELP PLZ

Put the summary of the bug you're having here

What I expected to happen was...:
i expected to be able to just play in a server or even single player and i cant do either of those.

What actually happened was...:
i get the error lang.nullexceptionpointer: group error every time i try and join a server.

Steps to Reproduce:
1. open my minecraft
2. try and connect to the server
3. get the error message agin.