1.21 Error

[xvrlee]

[04:28:02 INFO]: [IllegalStack] Enabling IllegalStack v2.9.11-SNAPSHOT-01
[04:28:02 ERROR]: Error occurred while enabling IllegalStack v2.9.11-SNAPSHOT-01 (Is it up to date?)
java.lang.IllegalArgumentException: No enum constant main.java.me.dniym.enums.ServerVersion.org.bukkit.craftbukkit
at java.base/java.lang.Enum.valueOf(Enum.java:293) ~[?:?]
at org.bukkit.craftbukkit.legacy.FieldRename.valueOf(FieldRename.java:57) ~[paper-1.21.jar:1.21-47-62ed302]
at IllegalStack-2.9.11.jar/main.java.me.dniym.enums.ServerVersion.BUKKIT_CUSTOM_METHOD_org_bukkit_craftbukkit_legacy_FieldRename_valueOf(ServerVersion.java) ~[IllegalStack-2.9.11.jar:?]
at IllegalStack-2.9.11.jar/main.java.me.dniym.enums.ServerVersion.valueOf(ServerVersion.java:3) ~[IllegalStack-2.9.11.jar:?]
at IllegalStack-2.9.11.jar/main.java.me.dniym.IllegalStack.setVersion(IllegalStack.java:1125) ~[IllegalStack-2.9.11.jar:?]
at IllegalStack-2.9.11.jar/main.java.me.dniym.IllegalStack.onEnable(IllegalStack.java:421) ~[IllegalStack-2.9.11.jar:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:288) ~[paper-api-1.21-R0.1-SNAPSHOT.jar:?]
at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[paper-1.21.jar:1.21-47-62ed302]
at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[paper-1.21.jar:1.21-47-62ed302]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:520) ~[paper-api-1.21-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:629) ~[paper-1.21.jar:1.21-47-62ed302]
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:578) ~[paper-1.21.jar:1.21-47-62ed302]
at net.minecraft.server.MinecraftServer.loadWorld0(MinecraftServer.java:752) ~[paper-1.21.jar:1.21-47-62ed302]
at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:514) ~[paper-1.21.jar:1.21-47-62ed302]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:327) ~[paper-1.21.jar:1.21-47-62ed302]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1219) ~[paper-1.21.jar:1.21-47-62ed302]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:329) ~[paper-1.21.jar:1.21-47-62ed302]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?]
[04:28:02 INFO]: [IllegalStack] Disabling IllegalStack v2.9.11-SNAPSHOT-01