MOT20 submission failed: child task failed

Dear MOTChallenge / Codabench Support Team,

I am experiencing repeated failures when submitting tracking results to the MOT20 test evaluation server. The platform displays the message:

“Submission failed: Child task failed or non-zero return code. See logs for more details.”

However, I cannot access any detailed logs or error messages through the submission page, so I am unable to identify the actual cause of the failure.

Some recent failed submission IDs are:

• ID 750468 — submitted on 2026-05-23 19:28
• ID 750431 — submitted on 2026-05-23 19:14
• ID 741036 — submitted on 2026-05-19 21:31
• ID 740936 — submitted on 2026-05-19 20:24

I have carefully checked the submitted ZIP files locally. Each submission contains the four required MOT20 test result files directly in the ZIP root directory:

• MOT20-04.txt
• MOT20-06.txt
• MOT20-07.txt
• MOT20-08.txt

The result files follow the standard MOTChallenge 10-column format, are not empty, and do not contain NaN or Inf values.

To further rule out an issue with my modified tracker, I also generated test results using the official FairMOT MOT20 model with the official MOT20 tracking setting (--test_mot20 True --conf_thres 0.3). The submission still failed with the same platform message.

Could you please help check the backend evaluation logs for these submissions and confirm whether there is currently an issue with the MOT20 evaluation worker or submission system? If the failure is caused by a specific formatting or submission requirement, I would be very grateful if you could let me know the exact reason.

I have attached a screenshot of the failed submissions for reference, and I can also provide the submitted ZIP file if needed.

Thank you very much for your time and assistance.

Best regards,
[Your Name]

Begin by checking the backend evaluation logs for submission IDs 750468, 750431, 741036, and 740936, then compare the failures with the reported MOT20 ZIP contents and submission requirements. Done means identifying the specific evaluation or worker error, or confirming an issue in the MOT20 evaluation system and documenting the required next step.