I've signed my main mod file to the Forge event bus, and annotated the handler routine with @EventHandler, but even though the client log says  "Sending event FMLModIdMappingEvent to mod UndergroundBiomes", I don't get it. The 1.6 -> 1.7 conversion is simply erasing all my blocks, and I need to look to see what's going on.

 

I've had the same problem with FMLMissingMappingsEvent.

Those events are not allowed to be sent, since they are not included in the list maintained by FMLModContainer.

    private static final Set<Class<? extends FMLEvent>> modEventTypes = ImmutableSet.<Class<? extends FMLEvent>>builder()
        .add(FMLPreInitializationEvent.class)
        .add(FMLInitializationEvent.class)
        .add(FMLPostInitializationEvent.class)
        .add(FMLServerAboutToStartEvent.class)
        .add(FMLServerStartingEvent.class)
        .add(FMLServerStartedEvent.class)
        .add(FMLServerStoppingEvent.class)
        .add(FMLServerStoppedEvent.class)
        .add(IMCEvent.class)
        .add(FMLFingerprintViolationEvent.class)
        .add(FMLModDisabledEvent.class)
        .build();

 

This is the class that seems to fire most of the FML events.

What version has that change. I was using 1039, recently that was the latest on the download page.