egametang/ET · error · Exception

exceed max file size

Error message

exceed max file size

What it means

Thrown by BundleFileReader.ReadFiles when a single file entry inside a Unity asset bundle reports a decompressed size >= int.MaxValue (~2 GiB). The reader allocates a managed MemoryStream whose capacity parameter is an int, so any entry at or above 2 GiB cannot be represented and the method aborts rather than silently truncating. The commented-out block beneath the throw shows an alternative using MemoryMappedFile that was disabled, confirming the hard limit is architectural, not accidental.

Solutions

1. Split the oversized asset into multiple smaller bundles so no single entry exceeds 2 GiB.
2. Verify the integrity of the bundle file — if the size looks wrong, the directory table may be corrupt; re-export the bundle from source.
3. If you control the reader and must support large files, re-enable the commented-out MemoryMappedFile path or switch to a FileStream-based extraction to disk instead of MemoryStream.
4. Audit the bundle's directory info before calling ReadFiles to reject or warn on oversized entries early.

Example fix

// before
file.stream = new MemoryStream((int)node.size);

// after — write large entries to disk instead of memory
if (node.size >= int.MaxValue)
{
    var extractPath = Path.Combine(Path.GetTempPath(), file.fileName);
    file.stream = new FileStream(extractPath, FileMode.Create, FileAccess.ReadWrite, FileShare.Read);
}
else
{
    file.stream = new MemoryStream((int)node.size);
}

long maxSize = int.MaxValue - 1; // ~2 GiB limit for MemoryStream capacity
foreach (var node in m_DirectoryInfo)
{
    if (node.size >= maxSize)
    {
        Debug.LogError($"File '{node.path}' size {node.size} exceeds the {maxSize} byte MemoryStream limit.");
        // split the bundle or switch to FileStream extraction
    }
}

try
{
    bundleFile.ReadFiles(blocksStream);
}
catch (Exception ex) when (ex.Message.Contains("exceed max file size"))
{
    Debug.LogError($"Bundle contains a file >= 2 GiB which cannot be loaded into memory. " +
        $"Split the asset or use a disk-based reader. Path: {bundlePath}");
}

When it happens

Trigger: Calling ReadFiles on a BundleFile whose m_DirectoryInfo[i].size field (read from the bundle's directory table) is >= 2,147,483,647 bytes. This happens when the bundle contains one very large uncompressed asset (e.g. a huge texture, video, or raw binary) or when the directory metadata is corrupt and reports an inflated size.

Common situations: Bundling large video or audio assets that exceed 2 GiB after decompression; corrupt or tampered bundle files with garbled directory entries; bundles generated by tooling that does not chunk large assets; attempting to unpack a deliberately crafted or malformed bundle during reverse-engineering.

Related errors

• too fig file

AI-assisted analysis of egametang/ET@5cab01f7a8 (2026-08-13). Data as JSON: /api/errors/9ffbd21bb6e2ad5c. Report an issue: GitHub.

Appendix: source

Thrown at Packages/cn.etetet.hybridclr/Scripts/Editor/Share/3rds/UnityFS/BundleFileReader.cs:185

            {
                blocksStream = new MemoryStream((int)uncompressedSizeSum);
            }
            return blocksStream;
        }

        public void ReadFiles(Stream blocksStream)
        {
            fileList = new StreamFile[m_DirectoryInfo.Length];
            for (int i = 0; i < m_DirectoryInfo.Length; i++)
            {
                var node = m_DirectoryInfo[i];
                var file = new StreamFile();
                fileList[i] = file;
                file.path = node.path;
                file.fileName = Path.GetFileName(node.path);
                if (node.size >= int.MaxValue)
                {
                    throw new Exception($"exceed max file size");
                    /*var memoryMappedFile = MemoryMappedFile.CreateNew(null, entryinfo_size);
                    file.stream = memoryMappedFile.CreateViewStream();*/
                    //var extractPath = path + "_unpacked" + Path.DirectorySeparatorChar;
                    //Directory.CreateDirectory(extractPath);
                    //file.stream = new FileStream(extractPath + file.fileName, FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite);
                }
                file.stream = new MemoryStream((int)node.size);
                blocksStream.Position = node.offset;
                blocksStream.CopyTo(file.stream, node.size);
                file.stream.Position = 0;
            }
        }

        private void ReadBlocks(EndianBinaryReader reader, Stream blocksStream)
        {
            foreach (var blockInfo in m_BlocksInfo)
            {
                var compressedSize = (int)blockInfo.compressedSize;

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