It may sound stupid to post this here on a server website but I have no were else to turn. I dont know of any possible reason this would happen. I can log in play some single player but as soon as I click connect on multiplayer my minecraft crashes. If any one has any idea what this is help me please.
Is there an error message? I would suggest completely removing all minecraft files (C:\Users\$youruser\Application Data\Roaming\.minecraft) and then redownload + reinstall minecraft, if there is no error. Also be aware that there are issues with multiplayer servers at the moment
Thank you very much tom although I have already reinstalled minecraft twice and removed all my single player mods it still crashes but thank you for informing of the server issues.