Server Wont Start

[Biggerbro]

I added all my mods and i am able to join the server and my friend is. But once i try to restart the server i get n error about "version check failed" and then nothing happens and the server never starts

[plowmanplow]

We will need FML logs, crash reports (if any), console logs, etc. Please also provide a link to the custom modpack for which you are attempting to create a server.