Serverside error io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information

I'm having this same problem may be caused by a incorrect version of forge

okay so i fixed it you need to make sure your runing the same forge as the server

okay i re added my mods and now I'm getting that error again

The errors displayed definitely showed that the Server was having issues with the mods you were adding. But I only saw the crash report that was prior to you saying that you fixed it.

I'd probably be able to determine what's going on if you send the most recent crash report. My guess is that something is wrong with the mod pack version.