Issue Description:

Minecraft server errors but not fatal.

What happens:

[16:24:36] [Server thread/ERROR] [FML]: Unable to construct net.minecraftforge.fml.common.Mod container
java.lang.reflect.InvocationTargetException: null
at sun.reflect.GeneratedConstructorAccessor19.newInstance(Unknown Source) ~[?:?]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_161]
at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:1.8.0_161]
at net.minecraftforge.fml.common.ModContainerFactory.build(ModContainerFactory.java:73) [ModContainerFactory.class:?]
at net.minecraftforge.fml.common.discovery.JarDiscoverer.findClassesASM(JarDiscoverer.java:114) [JarDiscoverer.class:?]
at net.minecraftforge.fml.common.discovery.JarDiscoverer.discover(JarDiscoverer.java:77) [JarDiscoverer.class:?]
at net.minecraftforge.fml.common.discovery.ContainerType.findMods(ContainerType.java:47) [ContainerType.class:?]
at net.minecraftforge.fml.common.discovery.ModCandidate.explore(ModCandidate.java:74) [ModCandidate.class:?]
at net.minecraftforge.fml.common.discovery.ModDiscoverer.identifyMods(ModDiscoverer.java:139) [ModDiscoverer.class:?]
at net.minecraftforge.fml.common.Loader.identifyMods(Loader.java:401) [Loader.class:?]
at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:541) [Loader.class:?]
at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:97) [FMLServerHandler.class:?]
at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:332) [FMLCommonHandler.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:125) [nz.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484) [MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_161]
Caused by: java.lang.IllegalArgumentException: The modId EnderIO must be all lowercase.
at net.minecraftforge.fml.common.FMLModContainer.sanityCheckModId(FMLModContainer.java:143) ~[FMLModContainer.class:?]
at net.minecraftforge.fml.common.FMLModContainer.(FMLModContainer.java:127) ~[FMLModContainer.class:?]
... 16 more

What you expected to happen:

Not error.

Steps to reproduce:

...

Affected Versions (Do not use "latest"):

• EnderIO: 3.1.183
• EnderCore: 0.5.18
• Minecraft: 1.12.2
• Forge: 14.23.2.2651

Your most recent log file where the issue was present:

Not sure which you need so I sent both
debug-1.log.gz
2018-04-02-5.log.gz

[pastebin/gist/etc link here]

That a mod for Minecraft 1.10.2 doesn't work on Minecraft 1.12.2 is not considered a bug.