Bambu Lab: Printer Stopped Working After Firmware Upgrade / Can't Start Prints Anymore

Overview

If your Bambu Lab printer stopped working with SimplyPrint after a firmware update, it is likely due to the new Authorization Control System introduced by Bambu Lab. This update prevents third-party integrations from starting prints, heating the printer, and sending movement commands.

For a full explanation of what this update means, see our detailed guide: Bambu Lab Security Firmware Authorization Control System Update.

Current Status (as of August, 2025)

• SimplyPrint still works with Bambu Lab printers, but some functions are restricted if you update to the latest firmware
• The latest firmware for the all printers includes these restrictions, but with LAN Only Mode and the new "Developer Mode" enabled, you can keep using SimplyPrint.
• X1Plus open-source firmware is unaffected and will continue working with SimplyPrint as it currently does. Learn more here: X1Plus Open-Source Firmware.

What You Can Do Now

Option 1: Downgrade Your Firmware

• For X1-series downgrade to LESS THAN 01.08.03.00
• For A1-series downgrade to LESS THAN 01.05.00.00
• For P1-series downgrade to LESS THAN 01.08.02.00
• For the H2D downgrade to LESS THAN01.01.00.01

The best immediate solution is to downgrade your firmware to a previous version that does not include these restrictions. Follow our firmware downgrade guide here: Bambu Lab: How to downgrade firmware

Option 2: Use LAN Only Mode with "Developer Mode" enabled

If you prefer to stay on the latest firmware, **"Developer Mode" **is now out for all Bambu Lab printers! This will restore SimplyPrint functionality when enabled with LAN mode.

Learn how to put your printer in LAN Only Mode, and how to enable Developer mode, here; Bambu Lab: LAN-only mode and developer mode - how to enable

Option 3: Use X1Plus Firmware (for X1 Series Owners)

If you are comfortable with custom firmware, X1Plus remains unaffected by this update and supports SimplyPrint without restrictions. You can explore X1Plus here: X1Plus Open-Source Firmware.

Final Thoughts

We are actively working with Bambu Lab to find an official solution and ensure SimplyPrint remains fully compatible with Bambu Lab printers. For now, downgrading your firmware is the best way to restore full SimplyPrint functionality.

Stay updated by following our announcements, and feel free to reach out if you have any questions!

Updated on: 31/08/2025