Presents Error

gistfile1.txt

[15:25:56 ERROR] [Sponge]: Could not pass GameInitializationEvent$Impl to Plugin{id=presents, name=Presents, version=1.1.0, description=A simple gift giving plugin, authors=[Zerthick], source=mods\Presents-1.1.0.jar}
java.lang.NoClassDefFoundError: io/github/zerthick/presents/present/data/mutable/PresentItemData
        at io.github.zerthick.presents.present.data.PresentData.registerData(PresentData.java:36) ~[PresentData.class:?]
        at io.github.zerthick.presents.Presents.onServerInit(Presents.java:101) ~[Presents.class:?]
        at org.spongepowered.common.event.listener.GameInitializationEventListener_Presents_onServerInit4.handle(Unknown Source) ~[?:?]
        at org.spongepowered.common.event.RegisteredListener.handle(RegisteredListener.java:95) ~[RegisteredListener.class:1.12.2-7.1.0-BETA-2]
        at org.spongepowered.common.event.SpongeEventManager.post(SpongeEventManager.java:407) [SpongeEventManager.class:1.12.2-7.1.0-BETA-2]
        at org.spongepowered.common.event.SpongeEventManager.post(SpongeEventManager.java:424) [SpongeEventManager.class:1.12.2-7.1.0-BETA-2]
        at org.spongepowered.common.event.SpongeEventManager.post(SpongeEventManager.java:428) [SpongeEventManager.class:1.12.2-7.1.0-BETA-2]
        at org.spongepowered.common.SpongeImpl.postState(SpongeImpl.java:211) [SpongeImpl.class:1.12.2-7.1.0-BETA-2]
        at org.spongepowered.server.SpongeVanilla.initialize(SpongeVanilla.java:145) [SpongeVanilla.class:1.12.2-7.1.0-BETA-2]
        at net.minecraft.server.dedicated.DedicatedServer.handler$onServerInitialize$zpi000(SourceFile:1243) [nz.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(SourceFile:191) [nz.class:?]
        at net.minecraft.server.MinecraftServer.run(SourceFile:434) [MinecraftServer.class:?]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_151]
Caused by: java.lang.ClassNotFoundException: io.github.zerthick.presents.present.data.mutable.PresentItemData
        at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_151]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_151]
        ... 13 more