everytime i try to join the public server it says i dont have the right version when i know i do have the right version

Can you show a picture of the message you get when trying to join? It will help us to solve your problem.

What version are you using? If you are using U48, the server is not updated yet to that version. You might also need to install the latest version of Forge.

oh the serves not up yet i guess thats the problem

 No, It is up, just only for u47 until the patch comes out.