[01:01:26 ERROR]: [FeatherBoard] java.lang.NoClassDefFoundError: net/scrayos/rankup/RankUp
        at be.maximvdw.placeholdercore.placeholders.RankupPlaceholderPack.onEnable(RankupPlaceholderPack.java:69)
        at be.maximvdw.featherboard.dk.registerPlaceHolder(dk.java:94)
        at be.maximvdw.featherboard.bX.a(bX.java:338)
        at be.maximvdw.featherboard.bX.a(bX.java:202)
        at be.maximvdw.featherboard.bX.a(bX.java:73)
        at be.maximvdw.featherboard.de.b(de.java:11)
        at be.maximvdw.featherboard.de.<init>(de.java:18)
        at be.maximvdw.featherboard.FeatherBoard.b(FeatherBoard.java:21)
        at be.maximvdw.featherboard.bv.j(bv.java:72)
        at be.maximvdw.featherboard.bv.onEnable(bv.java:22)
        at be.maximvdw.featherboard.FeatherBoard.onEnable(FeatherBoard.java:62)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:380)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:483)
        at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugin(CraftServer.java:501)
        at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugins(CraftServer.java:415)
        at net.minecraft.server.v1_16_R3.MinecraftServer.loadWorld(MinecraftServer.java:471)
        at net.minecraft.server.v1_16_R3.DedicatedServer.init(DedicatedServer.java:249)
        at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:942)
        at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:180)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassNotFoundException: net.scrayos.rankup.RankUp
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
        at java.base/java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:899)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 21 more