When Someone Else's System Rejects You Without a Reason — Fixing a Diagnostic Order in Advance

Description and use

An automation that uploads a ZIP archive to an external service failed with a 403 error that gave no explanation. The root cause was that the service only accepts .tar.gz archives. Rebuilding the archive in the correct format made the upload succeed on the first try, saving two days of work. A regression test was added to prevent recurrence.

Problem

An automation uploading a file to an external service failed with a 403 Forbidden response that gave no explanation, causing two days of wasted troubleshooting.

Outcome

Changing the archive format from ZIP to TAR.GZ resolved the 403 error, saving two days of work and preventing future format regressions.

Workflow

• 1. Build submission archive as ZIP
• 2. Upload archive to external service
• 3. Receive 403 Forbidden with no explanation
• 4. Assume authentication or permission issue and request user actions
• 5. Discover that the service requires TAR.GZ format
• 6. Rebuild archive as TAR.GZ
• 7. Upload again and succeed
• 8. Add regression test to enforce TAR.GZ format

Evidence

The archive was built as .zip, but that service accepts only .tar.gz.

Source

After changing the format, it passed on the first try.

Source