Interpretation
What this message does — and does not — prove
Official meaningBrother says paper is jammed in the 2-sided tray or inside the back cover/fuser path.
Do not assumeThis message does not by itself prove a bad duplex unit or fuser.
Safe sequence
Work through the manufacturer-scoped path
- 01
Leave the machine powered on long enough for the internal fan to cool hot parts before opening the specified area.
- 02
Remove the paper tray and inspect the 2-sided tray path without tearing the sheet.
- 03
Follow Brother's rear/fuser access procedure and remove all visible jammed paper.
- 04
Reload a straight, correctly sized stack and retry one controlled page.
Stop / escalate
When not to keep experimenting
If the message returns with no paper present, stop forcing rollers/covers and use Brother service guidance.