This document aims to organize and explain various transmission errors that may occur when send printing via a local area network (LAN) or wide area network (WAN).
| Error Code | Occurrence Scenario | Problem Brief Description |
| Upload Failed (7) | Printing from a MAC computer | Local network permission restriction |
| Upload Failed (9) | LAN printing via WIFI box | SD card not inserted |
| Upload Failed (25) | LAN printing via WIFI box | File write failure |
| Upload Failed (26) | When sending a print job | Upload failed; temporary files cleaned up |
| Upload Failed (28) | LAN printing | Firmware response timeout |
| Send Failed (55)/(56) | LAN printing | Network timeout or transmission failure |
| Upload Failed (1001)/(20008) | WAN printing | Computer username is in Chinese |
Scenario: Sending a print job from a MAC computer.
Cause: The macOS Privacy & Security settings prevent the slicing software from accessing the local network, making it unable to communicate with the printer on the LAN.
Solutions: You need to grant local network access permission to the slicing software in the system settings:
1. Open "System Settings" → "Privacy & Security" → "Local Network".
2. Find the Creality Print software you use in the application list, toggle on the permission switch, and allow access.
Scenario: Sending a print job via a WIFI box on the LAN.
Cause: The SD card required for file storage is not inserted into the WIFI box.
Solutions:
1. Insert a valid SD card into the SD card slot of the WIFI box.
2. After confirming the SD card is properly inserted, retry sending the print job.
Scenario: Sending a print job via a WIFI box on the LAN.
Description: The file system may fail to fully write the received data due to insufficient disk space, permission issues, or other file system errors.
Cause: SD/TF card file system error or insufficient storage space.
Solutions:
1. Remove the SD/TF card from the WIFI box.
2. Use a computer to format the card to FAT32 format (Note: Formatting will erase all data on the card; please back up data in advance).
3. Reinsert the card into the WIFI box and try sending the print job again.
Scenario: When sending a print job.
Description: If you leave the software idle for a long time after slicing the model, the computer system will clean up temporary files. Once the temporary files are deleted, the file no longer exists, leading to an error when sending the print job.
Cause: The temporary G-code file used for transmission has been cleaned up by the operating system.
Solutions:
1. Move or copy the model file to another location.
2. Use the moved model file to re-slice.
3. Immediately send the print job after slicing is completed; avoid leaving the software idle for a long time.
Scenario: LAN printing.
Description: The firmware takes too long to process G-code, resulting in a timeout. When waiting for the printer’s response, the slicing software does not receive any feedback from the printer firmware within the scheduled time. This usually happens when the printer firmware is processing complex G-code commands (such as a large number of small line segments), which requires a long calculation time that exceeds the software’s timeout limit.
Cause: The slicing software’s default timeout period is too short for the firmware to process complex G-code.
Solutions:
This issue has usually been fixed in subsequent software versions. Please update your slicing software to the latest version — the new version has extended the timeout judgment period from 10 seconds to 60 seconds to adapt to more scenarios.
Scenario: Sending a print job on the LAN.
Description: Weak Wi-Fi signal, network congestion, or an overly large G-code file causes the transmission time to be too long, leading to a timeout and failure in sending/receiving data.
Cause: Unstable or poor network connection, resulting in lost or delayed data packets during transmission.
Solutions:
1. Diagnose the network: Open the Terminal/Command Prompt on your computer, run the command ping <Printer IP Address> -t for a period of time, and check for packet loss or excessively high latency (usually should be <10ms).
1）Optimize the network environment:
2）Restart your router and network switch.
3）Ensure there are not too many obstacles between the printer and the router, and that the signal strength is good.
2. If the file is too large, try optimizing the model or reducing the slicing precision to decrease the G-code file size.
3. Resend the job: After improving the network environment, resend the print job.
Scenario: Sending a print job via WAN (remote network).
Cause: The slicing software or transmission service may fail to correctly recognize or encode Chinese characters when processing file paths, leading to communication abnormalities.
Solutions:
1. Temporary fix: Create a new administrator account with an English username on your computer, and perform slicing and printing under this account.
2. Permanent fix: Wait for a software update — subsequent versions of the slicing software will fix this Chinese path compatibility issue.