⚠
warning HP
Error Code Door is open
Printer cover or door is not fully secured — prevents operation.
? What Causes This
One or more printer doors or covers are open.
✓ How to Fix It
Secure all doors and covers on the printer.
Source: page 8 of the official manual
From the manual
This error code appears in:
HP Color Laserjet Pro M255 M256 Printer