lutzroeder/netron · error · Error

Expected ${this._position + length - this._length} more byte

Error message

Expected ${this._position + length - this._length} more bytes. The file might be corrupted. Unexpected end of file.

What it means

Thrown by the reader's internal _fill(length) when a read of `length` bytes starting at the current position would extend past the end of the stream. This fires on read/stream/peek operations after skip has already advanced the position, and indicates the declared structure is larger than the data available — i.e. a truncated or misidentified file.

Source

Thrown at source/browser.js:802

            return this._buffer.slice(position, position + length);
        }
        const position = this._start + this._position;
        this.skip(length);
        if (position % this._size === 0) {
            const index = Math.floor(position / this._size);
            const chunk = this._chunks[index];
            if (chunk && chunk.length === length) {
                return chunk;
            }
        }
        const buffer = new Uint8Array(length);
        this._read(buffer, position);
        return buffer;
    }

    _fill(length) {
        if (this._position + length > this._length) {
            throw new Error(`Expected ${this._position + length - this._length} more bytes. The file might be corrupted. Unexpected end of file.`);
        }
        if (!this._buffer || this._position < this._offset || this._position + length > this._offset + this._buffer.length) {
            this._offset = this._start + this._position;
            const length = Math.min(0x10000000, this._start + this._length - this._offset);
            if (!this._buffer || length !== this._buffer.length) {
                this._buffer = new Uint8Array(length);
            }
            this._read(this._buffer, this._offset);
        }
        const position = this._start + this._position - this._offset;
        this._position += length;
        return position;
    }

    _read(buffer, offset) {
        let index = Math.floor(offset / this._size);
        offset -= index * this._size;
        const chunk = this._chunks[index++];

View on GitHub (pinned to d8a543f5f8)

Solutions

Verify file integrity (checksum/size) of every input file, including external data companions
Ensure companion data files match the model version that references them (regenerate the export)
Check that the correct format handler is opening the file; a mis-detected format yields nonsense lengths
Re-export the model from the source framework and retry

Defensive patterns

Strategy: validation

Validate before calling

// Ensure remaining bytes cover the declared read length before reading
if (reader.position + length > reader.length) {
  throw new Error(`Need ${reader.position + length - reader.length} more bytes; file truncated`);
}

Try / catch

try {
  reader.read(length);
} catch (e) {
  if (/more bytes/.test(e.message)) {
    // input incomplete: stop parsing this section gracefully
  } else throw e;
}

Prevention

Validate companion data files' sizes against model metadata
Keep model and weights files versioned together as one unit
Fail fast on first out-of-bounds read instead of masking it

When it happens

Trigger: Any read of N bytes where this._position + N > this._length: reading a tensor blob, string, or sub-view whose declared size overruns the file; commonly triggered while decoding a binary protobuf or weights section with wrong offsets.

Common situations: External data files referenced by a model missing or mismatched (wrong version of the companion .bin), truncated transfers, or feeding a random/misidentified binary file to a model parser so parsed lengths are garbage.

Related errors

AI-assisted analysis of lutzroeder/netron@d8a543f5f8 (2026-08-27). Data as JSON: /api/errors/39380e4646ebbaf6. Report an issue: GitHub.