ComfyUI archive will not extract: check the archive before the destination

Scope and symptoms

CRC errors, Data Error and an unrecognized archive do not all have the same cause. Do not start a partially extracted Python environment while the integrity of its files remains unknown.

Search fragments; wording and context vary:

CRC Failed
Data Error
Can not open file as archive

Source-supported context

The 7-Zip recovery documentation distinguishes readable archive directories with damaged data from failures to recognize archive headers. Seeing a file listing does not establish that the executable files are intact or that the source is trustworthy. V04-ARCHIVE

Distinguish these cases

1. A transfer was truncated, or the downloaded file is an access-denied page instead of the release archive.

2. A multi-volume archive is missing a part, its filenames were changed, or the extractor does not support the format.

3. The archive passes its test but cannot be written completely because of space, permissions, path length or a locked destination file.

Suggested diagnostic sequence

This sequence is editorial guidance, not a diagnosis of your machine.

1. Record the release page, filename and download date. Compare publisher-provided size and checksum information when available, and keep every required volume together under its original name.

2. Run the archive utility's test function before extraction. If testing fails, obtain the same release again rather than treating the browser's completed-download indicator as an integrity check.

3. Extract a passing archive into a new, short, writable directory with adequate free space. Inspect the first failed file and do not merge a fresh extraction into an already damaged environment.

4. Start only after the archive test and extraction complete and the expected entry point exists. If a security product quarantines a file, investigate that warning separately instead of disabling protection.

Completion checks

There are no archive-test or extraction errors and the expected startup files are present. Model compatibility and GPU execution remain separate checks.

Limits and cautions

Hex-editing damaged executable archives is not an appropriate routine repair. For a downloadable release, obtaining and verifying an intact replacement leaves a clearer evidence trail.

Source review: 2026-09-22. No installation, GPU inference or user-environment repair was executed.

Original sources

• 7-Zip: recovering a corrupted archive · 2026-09-22

Related guides

• Model or runtime download failed: separate transport, access, integrity and storage
• Keep a reproducible ComfyUI repair record without exposing secrets