I downloaded the latest java 8 update and when i run the jar launcher it just says fetching new files, ive cleared the cache and redownloaded everything but i cant get it to work. I haven't played in quite a while so I dont know why I'm having trouble

Have you ensured you do not have a firewall blocking any access? Usually if it's hanging on "fetching new files", it usually means it's a connection issue to the server.

Regards,
Pyru