Hi, I recently created and got a custom modpack working through the launcher. I've also started a dedicated server for my friends to play on. However, every time I launch the server, it crashes after a few seconds and gives me the following report.
---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3
Time: 6/30/17 8:49 PM
Description: Exception in server tick loop
cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: net/minecraft/client/gui/GuiScreen