1.20.4 and beyond?

[koutsie]

Crashlog if it helps

[21:13:30] [Server thread/ERROR]: Error occurred while enabling CustomItemsLib v1.0.8 (Is it up to date?)
java.lang.NoClassDefFoundError: org/inventivetalent/update/spiget/UpdateCallback
	at one.lindegaard.CustomItemsLib.Core.onEnable(Core.java:182) ~[CustomItemsLib-1.0.8.jar:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:281) ~[purpur-api-1.20.4-R0.1-SNAPSHOT.jar:?]
	at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:190) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:104) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:507) ~[purpur-api-1.20.4-R0.1-SNAPSHOT.jar:?]
	at org.bukkit.craftbukkit.v1_20_R3.CraftServer.enablePlugin(CraftServer.java:651) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at org.bukkit.craftbukkit.v1_20_R3.CraftServer.enablePlugins(CraftServer.java:562) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at net.minecraft.server.MinecraftServer.loadWorld0(MinecraftServer.java:678) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:438) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:345) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1148) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:326) ~[purpur-1.20.4.jar:git-Purpur-2127]
	at java.lang.Thread.run(Thread.java:840) ~[?:?]
Caused by: java.lang.ClassNotFoundException: org.inventivetalent.update.spiget.UpdateCallback
	at org.bukkit.plugin.java.PluginClassLoader.loadClass0(PluginClassLoader.java:199) ~[purpur-api-1.20.4-R0.1-SNAPSHOT.jar:?]
	at org.bukkit.plugin.java.PluginClassLoader.loadClass(PluginClassLoader.java:166) ~[purpur-api-1.20.4-R0.1-SNAPSHOT.jar:?]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[?:?]
	... 13 more