Program: 11731
Project: 11731
Buggy source:
TridentWorld(String name,WorldLoader loader){
  ((TridentWorldLoader)loader).world=this;
  this.name=name;
  this.loader=loader;
  this.spawnPosition=Position.create(this,0,0,0);
  TridentLogger.get().log("String_Node_Str" + name + "String_Node_Str");
  File directory=new File(name + File.separator);
  File levelFile=new File(directory,"String_Node_Str");
  InputStream fis=null;
  try {
    fis=new FileInputStream(levelFile);
    byte[] compressedData=new byte[fis.available()];
    fis.read(compressedData);
    CompoundTag level=new NBTDecoder(new DataInputStream(new ByteArrayInputStream(ByteStreams.toByteArray(new GZIPInputStream(new ByteArrayInputStream(compressedData)))))).decode().getTagAs("String_Node_Str");
    TridentLogger.get().log("String_Node_Str");
    spawnPosition.setX(((IntTag)level.getTag("String_Node_Str")).value());
    spawnPosition.setY(((IntTag)level.getTag("String_Node_Str")).value() + 5);
    spawnPosition.setZ(((IntTag)level.getTag("String_Node_Str")).value());
    dimension=Dimension.OVERWORLD;
    difficulty=Difficulty.NORMAL;
    defaultGamemode=GameMode.of(((IntTag)level.getTag("String_Node_Str")).value());
    type=LevelType.of(((StringTag)level.getTag("String_Node_Str")).value());
    seed=((LongTag)level.getTag("String_Node_Str")).value();
    ((TridentWorldLoader)loader).setGenerator(seed);
    random=new GeneratorRandom(seed);
    borderSize=level.containsTag("String_Node_Str") ? ((DoubleTag)level.getTag("String_Node_Str")).value() : 6000;
    time.set(((LongTag)level.getTag("String_Node_Str")).value());
    existed.set(((LongTag)level.getTag("String_Node_Str")).value());
    raining=((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    rainTime.set(((IntTag)level.getTag("String_Node_Str")).value());
    thundering=((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    thunderTime.set(((IntTag)level.getTag("String_Node_Str")).value());
    difficultyLocked=level.containsTag("String_Node_Str") && ((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    WorldCreateOptions options=loader.options();
    options.dimension(dimension).difficulty(difficulty).gameMode(defaultGamemode).level(type).rule(gameRules).generator(null).structures(generateStructures).pvp(true).seed(String.valueOf(seed));
    TridentLogger.get().success("String_Node_Str");
  }
 catch (  FileNotFoundException ignored) {
    TridentLogger.get().error(new IllegalArgumentException("String_Node_Str" + name));
    return;
  }
catch (  Exception ex) {
    TridentLogger.get().error("String_Node_Str");
    TridentLogger.get().error(ex);
    return;
  }
 finally {
    settings=TridentWorldSettings.load(this,loader.options());
    try {
      if (fis != null) {
        fis.close();
      }
    }
 catch (    IOException e) {
      e.printStackTrace();
    }
  }
  File region=new File(directory,"String_Node_Str" + File.separator);
  if (!(region.exists()) || !(region.isDirectory())) {
    TridentLogger.get().error(new IllegalStateException("String_Node_Str"));
    return;
  }
  TridentLogger.get().success("String_Node_Str");
  TridentLogger.get().log("String_Node_Str");
  int centX=((int)Math.floor(spawnPosition.x())) >> 4;
  int centZ=((int)Math.floor(spawnPosition.z())) >> 4;
  for (  ChunkLocation location : new ChunkAxisAlignedBoundingBox(ChunkLocation.create(centX - 3,centZ - 3),ChunkLocation.create(centX + 3,centZ + 3))) {
    chunkAt(location,true);
  }
  TridentLogger.get().success("String_Node_Str");
  File playerData=new File(directory,"String_Node_Str");
  if (!(playerData.exists()) || !(playerData.isDirectory())) {
    TridentLogger.get().warn("String_Node_Str");
    playerData.mkdir();
  }
}

Fixed version (ground truth):
TridentWorld(String name,WorldLoader loader){
  ((TridentWorldLoader)loader).world=this;
  this.name=name;
  this.loader=loader;
  this.spawnPosition=Position.create(this,0,0,0);
  TridentLogger.get().log("String_Node_Str" + name + "String_Node_Str");
  File directory=new File(name + File.separator);
  File levelFile=new File(directory,"String_Node_Str");
  InputStream fis=null;
  try {
    fis=new FileInputStream(levelFile);
    byte[] compressedData=new byte[fis.available()];
    fis.read(compressedData);
    CompoundTag level=new NBTDecoder(new DataInputStream(new ByteArrayInputStream(ByteStreams.toByteArray(new GZIPInputStream(new ByteArrayInputStream(compressedData)))))).decode().getTagAs("String_Node_Str");
    TridentLogger.get().log("String_Node_Str");
    spawnPosition.setX(((IntTag)level.getTag("String_Node_Str")).value());
    spawnPosition.setY(((IntTag)level.getTag("String_Node_Str")).value() + 5);
    spawnPosition.setZ(((IntTag)level.getTag("String_Node_Str")).value());
    dimension=Dimension.OVERWORLD;
    difficulty=Difficulty.NORMAL;
    defaultGamemode=GameMode.of(((IntTag)level.getTag("String_Node_Str")).value());
    type=LevelType.of(((StringTag)level.getTag("String_Node_Str")).value());
    seed=((LongTag)level.getTag("String_Node_Str")).value();
    ((TridentWorldLoader)loader).setGenerator(seed);
    random=new GeneratorRandom(seed);
    borderSize=level.containsTag("String_Node_Str") ? ((DoubleTag)level.getTag("String_Node_Str")).value() : 6000;
    time.set(((LongTag)level.getTag("String_Node_Str")).value());
    existed.set(((LongTag)level.getTag("String_Node_Str")).value());
    raining=((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    rainTime.set(((IntTag)level.getTag("String_Node_Str")).value());
    thundering=((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    thunderTime.set(((IntTag)level.getTag("String_Node_Str")).value());
    difficultyLocked=level.containsTag("String_Node_Str") && ((ByteTag)level.getTag("String_Node_Str")).value() == 1;
    WorldCreateOptions options=loader.options();
    options.dimension(dimension).difficulty(difficulty).gameMode(defaultGamemode).level(type).generator(null).structures(generateStructures).pvp(true).seed(String.valueOf(seed));
    gameRules.forEach(options::rule);
    TridentLogger.get().success("String_Node_Str");
  }
 catch (  FileNotFoundException ignored) {
    TridentLogger.get().error(new IllegalArgumentException("String_Node_Str" + name));
    return;
  }
catch (  Exception ex) {
    TridentLogger.get().error("String_Node_Str");
    TridentLogger.get().error(ex);
    return;
  }
 finally {
    settings=TridentWorldSettings.load(this,loader.options());
    try {
      if (fis != null) {
        fis.close();
      }
    }
 catch (    IOException e) {
      e.printStackTrace();
    }
  }
  File region=new File(directory,"String_Node_Str" + File.separator);
  if (!(region.exists()) || !(region.isDirectory())) {
    TridentLogger.get().error(new IllegalStateException("String_Node_Str"));
    return;
  }
  TridentLogger.get().success("String_Node_Str");
  TridentLogger.get().log("String_Node_Str");
  int centX=((int)Math.floor(spawnPosition.x())) >> 4;
  int centZ=((int)Math.floor(spawnPosition.z())) >> 4;
  for (  ChunkLocation location : new ChunkAxisAlignedBoundingBox(ChunkLocation.create(centX - 3,centZ - 3),ChunkLocation.create(centX + 3,centZ + 3))) {
    chunkAt(location,true);
  }
  TridentLogger.get().success("String_Node_Str");
  File playerData=new File(directory,"String_Node_Str");
  if (!(playerData.exists()) || !(playerData.isDirectory())) {
    TridentLogger.get().warn("String_Node_Str");
    playerData.mkdir();
  }
}