[02:28:30 FATAL]: Error executing task
 java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: net/luckperms/api/LuckPermsProvider
        at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_282]
        at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_282]
        at net.minecraft.util.Util.func_181617_a(SourceFile:47) [h.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:846) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:467) [nz.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:784) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:630) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_282]
Caused by: java.lang.NoClassDefFoundError: net/luckperms/api/LuckPermsProvider
        at me.imystxc.whosonline.UIs.StaffUI.getOnlinePlayerButton(StaffUI.java:46) ~[StaffUI.class:2.0.0]
        at me.imystxc.whosonline.UIs.MainUI.lambda$menu$1(MainUI.java:62) ~[MainUI.class:2.0.0]
        at ca.landonjw.gooeylibs2.api.button.GooeyButton.onClick(GooeyButton.java:24) ~[GooeyButton.class:2.1.0]
        at ca.landonjw.gooeylibs2.implementation.GooeyContainer.func_184996_a(GooeyContainer.java:279) ~[GooeyContainer.class:2.1.0]
        at net.minecraft.network.NetHandlerPlayServer.func_147351_a(NetHandlerPlayServer.java:2126) ~[pa.class:?]
        at net.minecraft.network.play.client.CPacketClickWindow.func_148833_a(CPacketClickWindow.java:38) ~[lf.class:?]
        at net.minecraft.network.play.client.CPacketClickWindow.func_148833_a(CPacketClickWindow.java:12) ~[lf.class:?]
        at net.minecraft.network.PacketThreadUtil.lambda$checkThreadAndEnqueue$0(PacketThreadUtil.java:16) ~[hv.class:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_282]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_282]
        at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]
        ... 5 more
Caused by: java.lang.ClassNotFoundException: net.luckperms.api.LuckPermsProvider
        at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:101) ~[launchwrapper-1.12.jar:?]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_282]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_282]
        at me.imystxc.whosonline.UIs.StaffUI.getOnlinePlayerButton(StaffUI.java:46) ~[StaffUI.class:2.0.0]
        at me.imystxc.whosonline.UIs.MainUI.lambda$menu$1(MainUI.java:62) ~[MainUI.class:2.0.0]
        at ca.landonjw.gooeylibs2.api.button.GooeyButton.onClick(GooeyButton.java:24) ~[GooeyButton.class:2.1.0]
        at ca.landonjw.gooeylibs2.implementation.GooeyContainer.func_184996_a(GooeyContainer.java:279) ~[GooeyContainer.class:2.1.0]
        at net.minecraft.network.NetHandlerPlayServer.func_147351_a(NetHandlerPlayServer.java:2126) ~[pa.class:?]
        at net.minecraft.network.play.client.CPacketClickWindow.func_148833_a(CPacketClickWindow.java:38) ~[lf.class:?]
        at net.minecraft.network.play.client.CPacketClickWindow.func_148833_a(CPacketClickWindow.java:12) ~[lf.class:?]
        at net.minecraft.network.PacketThreadUtil.lambda$checkThreadAndEnqueue$0(PacketThreadUtil.java:16) ~[hv.class:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_282]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_282]
        at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]