Program: 51720
Project: 51720
Buggy source:
/** 
 * Called from the hook to start mod loading. We trigger the  {@link #identifyMods()} and Constructing, Preinitalization, and Initalization phases here. Finally,the mod list is frozen completely and is consider immutable from then on.
 */
public void loadMods(){
  initializeLoader();
  mods=Lists.newArrayList();
  GameData.fixupRegistries();
  namedMods=Maps.newHashMap();
  modController=new LoadController(this);
  modController.transition(LoaderState.LOADING,false);
  ModDiscoverer disc=identifyMods();
  ModAPIManager.INSTANCE.manageAPI(modClassLoader,disc);
  disableRequestedMods();
  modController.distributeStateMessage(FMLLoadEvent.class);
  sortModList();
  ModAPIManager.INSTANCE.cleanupAPIContainers(modController.getActiveModList());
  ModAPIManager.INSTANCE.cleanupAPIContainers(mods);
  mods=ImmutableList.copyOf(mods);
  for (  File nonMod : disc.getNonModLibs()) {
    if (nonMod.isFile()) {
      FMLLog.info("String_Node_Str",nonMod.getName());
      try {
        modClassLoader.addFile(nonMod);
      }
 catch (      MalformedURLException e) {
        FMLLog.log(Level.ERROR,e,"String_Node_Str",nonMod.getName());
      }
    }
  }
  modController.transition(LoaderState.CONSTRUCTING,false);
  modController.distributeStateMessage(LoaderState.CONSTRUCTING,modClassLoader,disc.getASMTable(),reverseDependencies);
  FMLLog.fine("String_Node_Str");
  for (  ModContainer mod : getActiveModList()) {
    FMLLog.fine("String_Node_Str",mod.getModId(),mod.getName(),mod.getVersion(),mod.getSource().getName(),CertificateHelper.getFingerprint(mod.getSigningCertificate()));
  }
  if (getActiveModList().isEmpty()) {
    FMLLog.fine("String_Node_Str");
  }
  modController.transition(LoaderState.PREINITIALIZATION,false);
  modController.distributeStateMessage(LoaderState.PREINITIALIZATION,disc.getASMTable(),canonicalConfigDir);
  GameData.freezeData();
  modController.transition(LoaderState.INITIALIZATION,false);
}

Fixed version (ground truth):
/** 
 * Called from the hook to start mod loading. We trigger the  {@link #identifyMods()} and Constructing, Preinitalization, and Initalization phases here. Finally,the mod list is frozen completely and is consider immutable from then on.
 */
public void loadMods(){
  initializeLoader();
  mods=Lists.newArrayList();
  namedMods=Maps.newHashMap();
  modController=new LoadController(this);
  modController.transition(LoaderState.LOADING,false);
  ModDiscoverer disc=identifyMods();
  ModAPIManager.INSTANCE.manageAPI(modClassLoader,disc);
  disableRequestedMods();
  modController.distributeStateMessage(FMLLoadEvent.class);
  sortModList();
  ModAPIManager.INSTANCE.cleanupAPIContainers(modController.getActiveModList());
  ModAPIManager.INSTANCE.cleanupAPIContainers(mods);
  mods=ImmutableList.copyOf(mods);
  for (  File nonMod : disc.getNonModLibs()) {
    if (nonMod.isFile()) {
      FMLLog.info("String_Node_Str",nonMod.getName());
      try {
        modClassLoader.addFile(nonMod);
      }
 catch (      MalformedURLException e) {
        FMLLog.log(Level.ERROR,e,"String_Node_Str",nonMod.getName());
      }
    }
  }
  modController.transition(LoaderState.CONSTRUCTING,false);
  modController.distributeStateMessage(LoaderState.CONSTRUCTING,modClassLoader,disc.getASMTable(),reverseDependencies);
  FMLLog.fine("String_Node_Str");
  for (  ModContainer mod : getActiveModList()) {
    FMLLog.fine("String_Node_Str",mod.getModId(),mod.getName(),mod.getVersion(),mod.getSource().getName(),CertificateHelper.getFingerprint(mod.getSigningCertificate()));
  }
  if (getActiveModList().isEmpty()) {
    FMLLog.fine("String_Node_Str");
  }
  modController.transition(LoaderState.PREINITIALIZATION,false);
  modController.distributeStateMessage(LoaderState.PREINITIALIZATION,disc.getASMTable(),canonicalConfigDir);
  modController.transition(LoaderState.INITIALIZATION,false);
}