C:\Users\Martynas\Desktop\CraftBukkit>java -Xms1024M -Xmx1024M -jar craftbukkit.
jar -o false
229 recipes
27 achievements
10:23:12 [INFO] Starting minecraft server version 1.5.1
10:23:12 [INFO] Loading properties
10:23:12 [INFO] Default game type: SURVIVAL
10:23:12 [INFO] Generating keypair
10:23:12 [INFO] Starting Minecraft server on *:25565
10:23:13 [INFO] This server is running CraftBukkit version git-Bukkit-1.4.7-R1.0
-94-g141dcf0-b2735jnks (MC: 1.5.1) (Implementing API version 1.5.1-R0.1)
10:23:13 [INFO] ----- Bukkit Auto Updater -----
10:23:13 [INFO] It appears that you're running a Beta Build, when you've specifi
ed in bukkit.yml that you prefer to run Recommended Builds.
10:23:13 [INFO] If you would like to be kept informed about new Beta Build relea
ses, it is recommended that you change 'preferred-channel' in your bukkit.yml to
 'beta'.
10:23:13 [INFO] With that set, you will be told whenever a new version is availa
ble for download, so that you can always keep up to date and secure with the lat
est fixes.
10:23:13 [INFO] If you would like to disable this warning, simply set 'suggest-c
hannels' to false in bukkit.yml.
10:23:13 [INFO] ----- ------------------- -----
10:23:13 [INFO] [PermissionsEx] sql backend registered!
10:23:13 [INFO] [PermissionsEx] file backend registered!
10:23:13 [INFO] [PermissionsEx] PermissionEx plugin initialized.
10:23:13 [SEVERE] Could not load 'plugins\Items4Killsv1-0.jar' in folder 'plugin
s'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError
: com/gmail/adamwoollen/Items4Kills/Items4Kills : Unsupported major.minor versio
n 51.0
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.j
ava:184)
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.
java:305)
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager
.java:230)
        at org.bukkit.craftbukkit.v1_5_R2.CraftServer.loadPlugins(CraftServer.ja
va:239)
        at org.bukkit.craftbukkit.v1_5_R2.CraftServer.<init>(CraftServer.java:21
7)
        at net.minecraft.server.v1_5_R2.PlayerList.<init>(PlayerList.java:55)
        at net.minecraft.server.v1_5_R2.DedicatedPlayerList.<init>(SourceFile:11
)
        at net.minecraft.server.v1_5_R2.DedicatedServer.init(DedicatedServer.jav
a:105)
        at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java
:379)
        at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:5
73)
Caused by: java.lang.UnsupportedClassVersionError: com/gmail/adamwoollen/Items4K
ills/Items4Kills : Unsupported major.minor version 51.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClassCond(Unknown Source)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$000(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader
.java:80)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.
java:53)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.j
ava:173)
        ... 9 more
>