Compiled from published third-party troubleshooting guides; eufy's in-app alert should show the same wording - confirm there if in doubt.
Error 1
Front bumper stuck
info
Bumper pressed in and not releasing.
Fix: Clean around the bumper and free it.
Error 2
Wheel stuck
warning
Debris blocking a drive wheel.
Fix: Clear the wheel wells of hair and debris.
Error 3
Side brush stuck
info
Debris wrapped in the side brush.
Fix: Remove and clean the side brush.
Error 4
Rolling (main) brush stuck
warning
Hair wrapped around the main brush.
Fix: Remove the main brush and clear it.
Error 5
Robot trapped
info
Physically boxed in.
Fix: Move it to open floor space.
Error 6
Robot suspended in the air
info
Wheel-drop sensor triggered, e.g. picked up or hanging off a step.
Fix: Place back on a flat floor and restart.