Internal error when trying to run any commands:

14.04 18:44:39 [Server] INFO at com.thevoxelbox.voxelsniper.VoxelSniperListener.commandSniperV(VoxelSniperListener.java:432)
14.04 18:44:39 [Server] INFO at com.thevoxelbox.voxelsniper.SniperPermissionHelper.getSniperInstance(SniperPermissionHelper.java:34)
14.04 18:44:39 [Server] INFO at com.thevoxelbox.voxelsniper.Sniper.(Sniper.java:98)
14.04 18:44:39 [Server] INFO at com.thevoxelbox.voxelsniper.SniperBrushes.getSniperBrushes(SniperBrushes.java:180)
14.04 18:44:39 [Server] INFO at com.thevoxelbox.voxelsniper.SniperBrushes.getBrush(SniperBrushes.java:240)
14.04 18:44:39 [Server] INFO at java.lang.Class.getConstructor(Unknown Source)
14.04 18:44:39 [Server] INFO at java.lang.Class.getConstructor0(Unknown Source)
14.04 18:44:39 [Server] INFO at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
14.04 18:44:39 [Server] INFO at java.lang.Class.getDeclaredConstructors0(Native Method)
14.04 18:44:39 [Server] INFO Caused by: java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R1/EntityLiving
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:409)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:476)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:580)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.DedicatedServerConnection.b(SourceFile:30)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.ServerConnection.b(SourceFile:35)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.PlayerConnection.d(PlayerConnection.java:110)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.NetworkManager.b(NetworkManager.java:292)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.Packet3Chat.handle(Packet3Chat.java:44)
14.04 18:44:39 [Server] INFO at com.bergerkiller.bukkit.common.internal.network.CommonPacketHandler$CommonPlayerConnection.a(CommonPacketHandler.java:480)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.PlayerConnection.a(PlayerConnection.java:841)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.PlayerConnection.chat(PlayerConnection.java:884)
14.04 18:44:39 [Server] INFO at net.minecraft.server.v1_5_R2.PlayerConnection.handleCommand(PlayerConnection.java:966)
14.04 18:44:39 [Server] INFO at org.bukkit.craftbukkit.v1_5_R2.CraftServer.dispatchCommand(CraftServer.java:523)
14.04 18:44:39 [Server] INFO at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
14.04 18:44:39 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
14.04 18:44:39 [Server] INFO org.bukkit.command.CommandException: Unhandled exception executing command 'v' in plugin VoxelSniper v5.168.5-SNAPSHOT-jnks201
14.04 18:44:39 [Server] SEVERE null

Voxel Sniper was working fine before 1.5

http://ci.thevoxelbox.com/job/VoxelSniper/

That's the version that I am using. . What are you trying to say?

No you don't. Just download and use it.

5.168.5 = v5.168.5 which is in the stack trace.

Anyways, I already tried updating not so many minutes ago.

It appears that you were right, I think I made a mistake with uploading the old one instead of the new one. Thanks for your help!