Type: Web / File Upload Vulnerability
Goal: Achieve remote code execution (RCE) or read the flag via malicious file upload.

Cause: Your local file was modified during the upload (e.g., an antivirus scanned and quarantined a section).
Fix: Disable real-time scanning for your temp directory. Re-hash the original source file and re-upload.

Standard HTML uploads fail with files over 2GB or on unstable connections.

Once all chunks are verified, the server generates a .gunner.manifest file. This manifest is the "key" to reassembly. Without this manifest, the raw chunks on the server are gibberish.

Because this is a closed ecosystem, errors are cryptic. Here is how to decode the most common failures.