Code here
[14:56:25] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception
java.lang.NoClassDefFoundError: org/spongepowered/common/event/SpongeCommonEventFactory
at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:3540) ~[MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:270) ~[nz.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486) [MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_144]
Caused by: java.lang.ClassNotFoundException: org.spongepowered.common.event.SpongeCommonEventFactory
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
… 4 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:521) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.Proxy.transform(Proxy.java:72) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
… 4 more
Caused by: java.lang.OutOfMemoryError: Java heap space
at org.spongepowered.asm.lib.tree.LabelNode.getLabel(LabelNode.java:60) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.lib.tree.LabelNode.accept(LabelNode.java:67) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.lib.tree.InsnList.accept(InsnList.java:162) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.lib.tree.MethodNode.accept(MethodNode.java:817) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.lib.tree.MethodNode.accept(MethodNode.java:727) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.lib.tree.ClassNode.accept(ClassNode.java:412) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.transformers.TreeTransformer.writeClass(TreeTransformer.java:82) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.writeClass(MixinTransformer.java:809) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.writeClass(MixinTransformer.java:803) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.applyMixins(MixinTransformer.java:715) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:509) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at org.spongepowered.asm.mixin.transformer.Proxy.transform(Proxy.java:72) ~[spongeforge-1.12.2-2768-7.1.4.jar:1.12.2-2768-7.1.4]
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_144]
… 4 more