[23:23:18] [Server thread/ERROR]: Error occurred while enabling SkinsRestorer v13.7.7-SNAPSHOT (Is it up to date?)
java.lang.ExceptionInInitializerError: null
    at skinsrestorer.bukkit.skinfactory.LegacySkinRefresher.<clinit>(LegacySkinRefresher.java:77) ~[?:?]
    at skinsrestorer.bukkit.skinfactory.UniversalSkinFactory.detectRefresh(UniversalSkinFactory.java:33) ~[?:?]
    at skinsrestorer.bukkit.skinfactory.UniversalSkinFactory.<init>(UniversalSkinFactory.java:14) ~[?:?]
    at skinsrestorer.bukkit.SkinsRestorer.onEnable(SkinsRestorer.java:76) ~[?:?]
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263) ~[spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:352) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:417) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at org.bukkit.craftbukkit.v1_15_R1.CraftServer.enablePlugin(CraftServer.java:462) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at org.bukkit.craftbukkit.v1_15_R1.CraftServer.enablePlugins(CraftServer.java:376) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:457) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at net.minecraft.server.v1_15_R1.DedicatedServer.init(DedicatedServer.java:267) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:784) [spigot-1.15.2.jar:git-Spigot-800b93f-8160e29]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]
Caused by: java.lang.NoSuchMethodException: no such method: org.bukkit.craftbukkit.v1_15_R1.entity.CraftPlayer.reregisterPlayer(EntityPlayer)void/invokeVirtual
    at java.lang.invoke.MemberName.makeAccessException(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MemberName$Factory.resolveOrFail(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MethodHandles$Lookup.findVirtual(Unknown Source) ~[?:1.8.0_241]
    at skinsrestorer.bukkit.skinfactory.LegacySkinRefresher.<clinit>(LegacySkinRefresher.java:47) ~[?:?]
    ... 12 more
Caused by: java.lang.NoSuchMethodError: org.bukkit.craftbukkit.v1_15_R1.entity.CraftPlayer.reregisterPlayer(Lnet/minecraft/server/v1_15_R1/EntityPlayer;)V
    at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_241]
    at java.lang.invoke.MemberName$Factory.resolve(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MemberName$Factory.resolveOrFail(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(Unknown Source) ~[?:1.8.0_241]
    at java.lang.invoke.MethodHandles$Lookup.findVirtual(Unknown Source) ~[?:1.8.0_241]
    at skinsrestorer.bukkit.skinfactory.LegacySkinRefresher.<clinit>(LegacySkinRefresher.java:47) ~[?:?]
    ... 12 more