Internal Error Occurs when trying to reload skripts

When I attempt to reload any of my skripts the error message " An internal error occurred while attempting to perform this comand" happens

here is the server console when attempting to do so

Please help

08.06 16:38:43 [Server] INFO CurrentlyPogging issued server command: /sk reload helpop
08.06 16:38:43 [Server] ERROR null
08.06 16:38:43 [Server] INFO org.bukkit.command.CommandException: Unhandled exception executing command 'sk' in plugin Skript v2.1.2
08.06 16:38:43 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:140) ~[craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:620) ~[craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1106) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:966) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(SourceFile:37) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(SourceFile:9) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_211]
08.06 16:38:43 [Server] INFO at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_211]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:673) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:335) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:629) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:537) [craftbukkit45.jar:git-Bukkit-12698ea]
08.06 16:38:43 [Server] INFO at java.lang.Thread.run(Thread.java:748) [?:1.8.0_211]
08.06 16:38:43 [Server] INFO Caused by: java.lang.NoSuchMethodError: ch.njol.util.NonNullPair.getSecond()Ljava/lang/Object;
08.06 16:38:43 [Server] INFO at ch.njol.skript.command.Commands.loadCommand(Commands.java:379) ~[?:?]
08.06 16:38:43 [Server] INFO at ch.njol.skript.ScriptLoader.loadScript(ScriptLoader.java:462) ~[?:?]
08.06 16:38:43 [Server] INFO at ch.njol.skript.ScriptLoader.loadScripts(ScriptLoader.java:262) ~[?:?]
08.06 16:38:43 [Server] INFO at ch.njol.skript.SkriptCommand.onCommand(SkriptCommand.java:155) ~[?:?]
08.06 16:38:43 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit45.jar:git-Bukkit-12698ea]