Server Crash in Fabric Version

[Flogah]

When trying to launch a server while this is in the mod list, the server crashes.
No crashing when using the client.

[dxkyy]

same issue. this error message shows when trying to start the server:

[23:57:17] [main/ERROR]: Failed to start the minecraft server
java.lang.RuntimeException: Could not execute entrypoint stage 'main' due to errors, provided by 'guardribbits' at 'sunbatheproductions28.guardribbits.GuardRibbitsFabric'!
	at net.fabricmc.loader.impl.FabricLoaderImpl.lambda$invokeEntrypoints$0(FabricLoaderImpl.java:409) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.util.ExceptionUtil.gatherExceptions(ExceptionUtil.java:33) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.FabricLoaderImpl.invokeEntrypoints(FabricLoaderImpl.java:407) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.game.minecraft.Hooks.startServer(Hooks.java:63) ~[fabric-loader-0.17.3.jar:?]
	at net.minecraft.server.Main.main(Main.java:112) ~[server-intermediary.jar:?]
	at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:506) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:72) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.launch.knot.KnotServer.main(KnotServer.java:23) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.launch.server.FabricServerLauncher.main(FabricServerLauncher.java:69) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.installer.ServerLauncher.main(ServerLauncher.java:69) ~[fabric-server-mc.1.20.1-loader.0.17.3-launcher.1.1.0.jar:1.1.0]
Caused by: java.lang.NoClassDefFoundError: net/minecraft/class_5617
	at sunbatheproductions28.guardribbits.GuardRibbitsFabric.onInitialize(GuardRibbitsFabric.java:16) ~[GuardRibbits-1.20.1-Fabric-1.0.4.jar:?]
	at net.fabricmc.loader.impl.FabricLoaderImpl.invokeEntrypoints(FabricLoaderImpl.java:405) ~[fabric-loader-0.17.3.jar:?]
	... 7 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.class_5617
	at jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source) ~[?:?]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:?]
	at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.loadClass(KnotClassDelegate.java:239) ~[fabric-loader-0.17.3.jar:?]
	at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:119) ~[fabric-loader-0.17.3.jar:?]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:?]
	at sunbatheproductions28.guardribbits.GuardRibbitsFabric.onInitialize(GuardRibbitsFabric.java:16) ~[GuardRibbits-1.20.1-Fabric-1.0.4.jar:?]
	at net.fabricmc.loader.impl.FabricLoaderImpl.invokeEntrypoints(FabricLoaderImpl.java:405) ~[fabric-loader-0.17.3.jar:?]
	... 7 more