Solved Jar issues [FIXED]

I am having a issue that is majorly confusing me. This error starting when about 2 hours ago I switched to the 1.9.4 jar instead of 1.9 jar, now every time I load up my plugin - It loads up fine, but then when I try to use a command, no matter what command it is, it says getItemInMainHand() is undefined also with END_ROD, both of them I am using in my plugin, but even when it isn't in the current command, here is the log:

Log (open) Log (close)

[17:07:25] [Server thread/INFO]: Starting minecraft server version 1.9
[17:07:25] [Server thread/INFO]: Loading properties
[17:07:25] [Server thread/WARN]: ressource-pack-hash is depricated and found along side resource-pack-sha1. resource-pack-hash will be ignored.
[17:07:25] [Server thread/INFO]: Default game type: SURVIVAL
[17:07:26] [Server thread/INFO]: This server is running CraftBukkit version git-Spigot-2038f4a-cd36f6f (MC: 1.9) (Implementing API version 1.9-R0.1-SNAPSHOT)
[17:07:26] [Server thread/INFO]: Debug logging is disabled
[17:07:26] [Server thread/INFO]: Server Ping Player Sample Count: 12
[17:07:26] [Server thread/INFO]: Using 4 threads for Netty based IO
[17:07:26] [Server thread/INFO]: Generating keypair
[17:07:26] [Server thread/INFO]: Starting Minecraft server on 192.168.0.80:25565
[17:07:26] [Server thread/INFO]: Using default channel type
[17:07:26] [Server thread/INFO]: Set PluginClassLoader as parallel capable
[17:07:26] [Server thread/INFO]: [DevServer] Loading DevServer v1.0
[17:07:26] [Server thread/INFO]: [TextSpeaker] Loading TextSpeaker v1.0
[17:07:26] [Server thread/INFO]: [WorldEdit] Loading WorldEdit v6.1;no_git_id
[17:07:26] [Server thread/INFO]: [Installer] Loading Installer v2.3.2-1
[17:07:26] [Server thread/INFO]: **** Beginning UUID conversion, this may take A LONG time ****
[17:07:26] [Server thread/INFO]: Preparing level "world"
[17:07:26] [Server thread/INFO]: -------- World Settings For [world] --------
[17:07:26] [Server thread/INFO]: Item Despawn Rate: 6000
[17:07:26] [Server thread/INFO]: Item Merge Radius: 2.5
[17:07:26] [Server thread/INFO]: Allow Zombie Pigmen to spawn from portal blocks: true
[17:07:26] [Server thread/INFO]: Experience Merge Radius: 3.0
[17:07:26] [Server thread/INFO]: Arrow Despawn Rate: 1200
[17:07:26] [Server thread/INFO]: Random Lighting Updates: false
[17:07:26] [Server thread/INFO]: Mob Spawn Range: 4
[17:07:26] [Server thread/INFO]: Entity Tracking Range: Pl 48 / An 48 / Mo 48 / Mi 32 / Other 64
[17:07:26] [Server thread/INFO]: Cactus Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Cane Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Melon Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Mushroom Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Pumpkin Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Sapling Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Wheat Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: NetherWart Growth Modifier: 100%
[17:07:26] [Server thread/INFO]: Entity Activation Range: An 32 / Mo 32 / Mi 16
[17:07:26] [Server thread/INFO]: Structure Info Saving: true
[17:07:26] [Server thread/INFO]: Max TNT Explosions: 100
[17:07:26] [Server thread/INFO]: Nerfing mobs spawned from spawners: false
[17:07:26] [Server thread/INFO]: Tile Max Tick Time: 50ms Entity max Tick Time: 50ms
[17:07:26] [Server thread/INFO]: Hopper Transfer: 8 Hopper Check: 8 Hopper Amount: 1
[17:07:26] [Server thread/INFO]: Max Entity Collisions: 8
[17:07:26] [Server thread/INFO]: Custom Map Seeds: Village: 10387312 Feature: 14357617
[17:07:26] [Server thread/INFO]: Zombie Aggressive Towards Villager: true
[17:07:26] [Server thread/INFO]: View Distance: 10
[17:07:27] [Server thread/INFO]: -------- World Settings For [world_nether] --------
[17:07:27] [Server thread/INFO]: Item Despawn Rate: 6000
[17:07:27] [Server thread/INFO]: Item Merge Radius: 2.5
[17:07:27] [Server thread/INFO]: Allow Zombie Pigmen to spawn from portal blocks: true
[17:07:27] [Server thread/INFO]: Experience Merge Radius: 3.0
[17:07:27] [Server thread/INFO]: Arrow Despawn Rate: 1200
[17:07:27] [Server thread/INFO]: Random Lighting Updates: false
[17:07:27] [Server thread/INFO]: Mob Spawn Range: 4
[17:07:27] [Server thread/INFO]: Entity Tracking Range: Pl 48 / An 48 / Mo 48 / Mi 32 / Other 64
[17:07:27] [Server thread/INFO]: Cactus Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Cane Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Melon Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Mushroom Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Pumpkin Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Sapling Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Wheat Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: NetherWart Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Entity Activation Range: An 32 / Mo 32 / Mi 16
[17:07:27] [Server thread/INFO]: Structure Info Saving: true
[17:07:27] [Server thread/INFO]: Max TNT Explosions: 100
[17:07:27] [Server thread/INFO]: Nerfing mobs spawned from spawners: false
[17:07:27] [Server thread/INFO]: Tile Max Tick Time: 50ms Entity max Tick Time: 50ms
[17:07:27] [Server thread/INFO]: Hopper Transfer: 8 Hopper Check: 8 Hopper Amount: 1
[17:07:27] [Server thread/INFO]: Max Entity Collisions: 8
[17:07:27] [Server thread/INFO]: Custom Map Seeds: Village: 10387312 Feature: 14357617
[17:07:27] [Server thread/INFO]: Zombie Aggressive Towards Villager: true
[17:07:27] [Server thread/INFO]: View Distance: 10
[17:07:27] [Server thread/INFO]: -------- World Settings For [world_the_end] --------
[17:07:27] [Server thread/INFO]: Item Despawn Rate: 6000
[17:07:27] [Server thread/INFO]: Item Merge Radius: 2.5
[17:07:27] [Server thread/INFO]: Allow Zombie Pigmen to spawn from portal blocks: true
[17:07:27] [Server thread/INFO]: Experience Merge Radius: 3.0
[17:07:27] [Server thread/INFO]: Arrow Despawn Rate: 1200
[17:07:27] [Server thread/INFO]: Random Lighting Updates: false
[17:07:27] [Server thread/INFO]: Mob Spawn Range: 4
[17:07:27] [Server thread/INFO]: Entity Tracking Range: Pl 48 / An 48 / Mo 48 / Mi 32 / Other 64
[17:07:27] [Server thread/INFO]: Cactus Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Cane Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Melon Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Mushroom Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Pumpkin Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Sapling Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Wheat Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: NetherWart Growth Modifier: 100%
[17:07:27] [Server thread/INFO]: Entity Activation Range: An 32 / Mo 32 / Mi 16
[17:07:27] [Server thread/INFO]: Structure Info Saving: true
[17:07:27] [Server thread/INFO]: Max TNT Explosions: 100
[17:07:27] [Server thread/INFO]: Nerfing mobs spawned from spawners: false
[17:07:27] [Server thread/INFO]: Tile Max Tick Time: 50ms Entity max Tick Time: 50ms
[17:07:27] [Server thread/INFO]: Hopper Transfer: 8 Hopper Check: 8 Hopper Amount: 1
[17:07:27] [Server thread/INFO]: Max Entity Collisions: 8
[17:07:27] [Server thread/INFO]: Custom Map Seeds: Village: 10387312 Feature: 14357617
[17:07:27] [Server thread/INFO]: Zombie Aggressive Towards Villager: true
[17:07:27] [Server thread/INFO]: View Distance: 10
[17:07:27] [Server thread/INFO]: Preparing start region for level 0 (Seed: 4187679866722887561)
[17:07:28] [Server thread/INFO]: Preparing start region for level 1 (Seed: 7528202622071883986)
[17:07:29] [Server thread/INFO]: Preparing spawn area: 40%
[17:07:30] [Server thread/INFO]: Preparing spawn area: 86%
[17:07:30] [Server thread/INFO]: Preparing start region for level 2 (Seed: 7528202622071883986)
[17:07:31] [Server thread/INFO]: [DevServer] Enabling DevServer v1.0
[17:07:31] [Server thread/INFO]: [TextSpeaker] Enabling TextSpeaker v1.0
[17:07:31] [Server thread/INFO]: [WorldEdit] Enabling WorldEdit v6.1;no_git_id
[17:07:31] [Server thread/INFO]: WEPIF: Using the Bukkit Permissions API.
[17:07:31] [Server thread/WARN]: [WorldEdit]
**********************************************
** This WorldEdit version does not fully support your version of Bukkit.
**
** When working with blocks or undoing, chests will be empty, signs
** will be blank, and so on. There will be no support for entity
** and biome-related functions.
**
** Please see http://wiki.sk89q.com/wiki/WorldEdit/Bukkit_adapters
**********************************************

[17:07:31] [Server thread/INFO]: [Installer] Enabling Installer v2.3.2-1
[17:07:31] [Server thread/INFO]: Server permissions file permissions.yml is empty, ignoring it
[17:07:31] [Server thread/INFO]: Done (4.963s)! For help, type "help" or "?"
[17:08:04] [User Authenticator #1/INFO]: UUID of player Benwager12 is 36008b4b-94ea-440e-8de2-685db8530e85
[17:08:05] [Server thread/INFO]: Benwager12[/192.168.0.80:55073] logged in with entity id 90 at ([world]34.55391018808477, 108.0, 18.869323014880806)
[17:08:25] [Server thread/INFO]: Benwager12 issued server command: /hat
[17:08:25] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'hat' in plugin DevServer v1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-2038f4a-cd36f6f]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-2038f4a-cd36f6f]
at org.bukkit.craftbukkit.v1_9_R1.CraftServer.dispatchCommand(CraftServer.java:645) ~[spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.PlayerConnection.handleCommand(PlayerConnection.java:1350) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.PlayerConnection.a(PlayerConnection.java:1185) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_51]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_51]
at net.minecraft.server.v1_9_R1.SystemUtils.a(SourceFile:45) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.MinecraftServer.D(MinecraftServer.java:721) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.DedicatedServer.D(DedicatedServer.java:400) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.MinecraftServer.C(MinecraftServer.java:660) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:559) [spigot.jar:git-Spigot-2038f4a-cd36f6f]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51]
Caused by: java.lang.Error: Unresolved compilation problems:
END_ROD cannot be resolved or is not a field
END_ROD cannot be resolved or is not a field
END_ROD cannot be resolved or is not a field
The method getItemInMainHand() is undefined for the type PlayerInventory

at com.benwager12.devserver.DevServer.onCommand(DevServer.java:89) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-2038f4a-cd36f6f]
... 15 more
[17:09:07] [Server thread/INFO]: Stopping the server
[17:09:07] [Server thread/INFO]: Stopping server
[17:09:07] [Server thread/INFO]: [Installer] Disabling Installer v2.3.2-1
[17:09:07] [Server thread/INFO]: [WorldEdit] Disabling WorldEdit v6.1;no_git_id
[17:09:07] [Server thread/INFO]: [TextSpeaker] Disabling TextSpeaker v1.0
[17:09:07] [Server thread/INFO]: [DevServer] Disabling DevServer v1.0
[17:09:07] [Server thread/INFO]: Saving players
[17:09:07] [Server thread/INFO]: Benwager12 lost connection: Server closed
[17:09:07] [Server thread/INFO]: Benwager12 left the game.
[17:09:07] [Server thread/INFO]: Saving worlds
[17:09:07] [Server thread/INFO]: Saving chunks for level 'world'/Overworld
[17:09:07] [Server thread/INFO]: Saving chunks for level 'world_nether'/Nether
[17:09:07] [Server thread/INFO]: Saving chunks for level 'world_the_end'/The End

and if you would like snippets of the code that I have then please post in the comments, I will not be able to do this until Sunday and someone will probably know how to do this before then.

EDIT: I have realised within minutes of posting this that something in 1.9 cannot be in the same method, even though the server is in 1.9 and uses the same jar as the plugin, although this only happens for my plugins and it works for others,




EDIT 2: I think I somehow did something right, it's fixed and I have no idea how... Everything is working correctly........... Moderators if you see this feel free to delete it as spam because it isn't really helping anyone, I guess the moral is feel free to test, and when you do keep checking in the case it fixes it's self.