Kyocera TASKalfa MZ4000i/MZ3200i FAX platform — E/U04400
Kyocera E/U04400 means the transmit encryption key does not match the recipient. The guidance here is specific to TASKalfa MZ4000i/MZ3200i FAX platform and the Fax/encryption key operation.
Error meaning
The transmit encryption key does not match the recipient.
This interpretation is tied to the reviewed family/platform and subsystem. Do not reuse the code by itself on another printer family.
Applies to
TASKalfa MZ4000i/MZ3200i FAX platform
- TASKalfa MZ4000i
- TASKalfa MZ3200i
Common formatting
These are lookup/formatting aliases for this reviewed condition, not separate pages.
- E/U04400
What usually causes it
- The encryption key selected for transmission does not match the key expected by the receiving fax. The destination can support encrypted communication, but both ends are not using the same registered key.
- The exact condition recorded for this code is: The transmit encryption key does not match the recipient.
- Select the correct registered transmit encryption key for that recipient and verify the key assignment in the saved fax destination. Avoid deleting other keys while correcting one destination.
What to try
Check the condition this code actually names
Select the matching registered encryption key and retry.
Isolate the affected part of the workflow
Select the correct registered transmit encryption key for that recipient and verify the key assignment in the saved fax destination. Avoid deleting other keys while correcting one destination.
Run a controlled confirmation test
Send a short encrypted test after the key selection matches. If the job completes, keep the corrected key association with that recipient and leave unrelated fax security settings unchanged.
After each corrective action
Retry the original operation that produced E/U04400. If it works, stop there rather than moving into unrelated troubleshooting.
If the code returns
If E/U04400 repeats, have administrators on both ends compare the key identifier or registration assignment without sending the secret key through insecure channels.
When service may be needed
Do not guess, expose, or bypass encryption keys. Key changes belong to authorized fax/security administrators.
Continue with guided troubleshooting
If the printer still is not working after the reviewed checks, carry this verified error context into the guided troubleshooter.
Related information
Verified source
Official two-model FAX guide. Error Code List establishes fax/i-FAX meanings and family scope; public guidance is independently paraphrased.