Program: 178147
Project: 178147
Buggy source:
/** 
 * Tries to load mod configuration from file, with error handling. If it fails, the config attribute will remain null.
 * @param config
 */
private boolean loadConfig(){
  try {
    if (!(InvTweaksItemTreeLoader.isValidVersion(InvTweaksConst.CONFIG_TREE_FILE))) {
      backupFile(new File(InvTweaksConst.CONFIG_TREE_FILE),InvTweaksConst.CONFIG_TREE_FILE);
    }
  }
 catch (  Exception e) {
    log.warning("String_Node_Str" + e.getMessage());
  }
  if (new File(InvTweaksConst.OLDER_CONFIG_RULES_FILE).exists()) {
    if (new File(InvTweaksConst.CONFIG_RULES_FILE).exists()) {
      backupFile(new File(InvTweaksConst.CONFIG_RULES_FILE),InvTweaksConst.CONFIG_RULES_FILE);
    }
    new File(InvTweaksConst.OLDER_CONFIG_RULES_FILE).renameTo(new File(InvTweaksConst.CONFIG_RULES_FILE));
  }
  if (new File(InvTweaksConst.OLDER_CONFIG_TREE_FILE).exists()) {
    backupFile(new File(InvTweaksConst.OLDER_CONFIG_TREE_FILE),InvTweaksConst.CONFIG_TREE_FILE);
  }
  if (new File(InvTweaksConst.OLD_CONFIG_TREE_FILE).exists()) {
    new File(InvTweaksConst.OLD_CONFIG_TREE_FILE).renameTo(new File(InvTweaksConst.CONFIG_TREE_FILE));
  }
  if (!new File(InvTweaksConst.CONFIG_RULES_FILE).exists() && extractFile(InvTweaksConst.DEFAULT_CONFIG_FILE,InvTweaksConst.CONFIG_RULES_FILE)) {
    InvTweaks.logInGameStatic(InvTweaksConst.CONFIG_RULES_FILE + "String_Node_Str" + InvTweaksLocalization.get("String_Node_Str"));
  }
  if (!new File(InvTweaksConst.CONFIG_TREE_FILE).exists() && extractFile(InvTweaksConst.DEFAULT_CONFIG_TREE_FILE,InvTweaksConst.CONFIG_TREE_FILE)) {
    InvTweaks.logInGameStatic(InvTweaksConst.CONFIG_TREE_FILE + "String_Node_Str" + InvTweaksLocalization.get("String_Node_Str"));
  }
  storedConfigLastModified=computeConfigLastModified();
  String error=null;
  try {
    if (config == null) {
      config=new InvTweaksConfig(InvTweaksConst.CONFIG_RULES_FILE,InvTweaksConst.CONFIG_TREE_FILE);
      autoRefillHandler=new InvTweaksHandlerAutoRefill(mc,config);
      shortcutsHandler=new InvTweaksHandlerShortcuts(mc,config);
    }
    config.load();
    shortcutsHandler.loadShortcuts();
    log.setLevel(config.getLogLevel());
    InvTweaks.logInGameStatic("String_Node_Str");
    showConfigErrors(config);
  }
 catch (  FileNotFoundException e) {
    error="String_Node_Str";
  }
catch (  Exception e) {
    error="String_Node_Str" + e.getMessage();
  }
  if (error != null) {
    InvTweaks.logInGameStatic(error);
    log.severe(error);
    config=null;
    return false;
  }
 else {
    return true;
  }
}

Fixed version (ground truth):
/** 
 * Tries to load mod configuration from file, with error handling. If it fails, the config attribute will remain null.
 * @param config
 */
private boolean loadConfig(){
  try {
    if (!(InvTweaksItemTreeLoader.isValidVersion(InvTweaksConst.CONFIG_TREE_FILE))) {
      backupFile(new File(InvTweaksConst.CONFIG_TREE_FILE),InvTweaksConst.CONFIG_TREE_FILE);
    }
  }
 catch (  Exception e) {
    log.warning("String_Node_Str" + e.getMessage());
  }
  if (new File(InvTweaksConst.OLDER_CONFIG_RULES_FILE).exists()) {
    if (new File(InvTweaksConst.CONFIG_RULES_FILE).exists()) {
      backupFile(new File(InvTweaksConst.CONFIG_RULES_FILE),InvTweaksConst.CONFIG_RULES_FILE);
    }
    new File(InvTweaksConst.OLDER_CONFIG_RULES_FILE).renameTo(new File(InvTweaksConst.CONFIG_RULES_FILE));
  }
  if (new File(InvTweaksConst.OLDER_CONFIG_TREE_FILE).exists()) {
    backupFile(new File(InvTweaksConst.OLDER_CONFIG_TREE_FILE),InvTweaksConst.CONFIG_TREE_FILE);
  }
  if (new File(InvTweaksConst.OLD_CONFIG_TREE_FILE).exists()) {
    new File(InvTweaksConst.OLD_CONFIG_TREE_FILE).renameTo(new File(InvTweaksConst.CONFIG_TREE_FILE));
  }
  if (!new File(InvTweaksConst.CONFIG_RULES_FILE).exists() && extractFile(InvTweaksConst.DEFAULT_CONFIG_FILE,InvTweaksConst.CONFIG_RULES_FILE)) {
    InvTweaks.logInGameStatic(InvTweaksConst.CONFIG_RULES_FILE + "String_Node_Str" + InvTweaksLocalization.get("String_Node_Str"));
  }
  if (!new File(InvTweaksConst.CONFIG_TREE_FILE).exists() && extractFile(InvTweaksConst.DEFAULT_CONFIG_TREE_FILE,InvTweaksConst.CONFIG_TREE_FILE)) {
    InvTweaks.logInGameStatic(InvTweaksConst.CONFIG_TREE_FILE + "String_Node_Str" + InvTweaksLocalization.get("String_Node_Str"));
  }
  storedConfigLastModified=computeConfigLastModified();
  String error=null;
  Exception errorException=null;
  try {
    if (config == null) {
      config=new InvTweaksConfig(InvTweaksConst.CONFIG_RULES_FILE,InvTweaksConst.CONFIG_TREE_FILE);
      autoRefillHandler=new InvTweaksHandlerAutoRefill(mc,config);
      shortcutsHandler=new InvTweaksHandlerShortcuts(mc,config);
    }
    config.load();
    shortcutsHandler.loadShortcuts();
    log.setLevel(config.getLogLevel());
    InvTweaks.logInGameStatic("String_Node_Str");
    showConfigErrors(config);
  }
 catch (  FileNotFoundException e) {
    error="String_Node_Str";
  }
catch (  Exception e) {
    error="String_Node_Str";
    errorException=e;
  }
  if (error != null) {
    InvTweaks.logInGameErrorStatic(error,errorException);
    log.severe(error);
    config=null;
    return false;
  }
 else {
    return true;
  }
}