If you see the Android error icon as the following picture, please follow the steps below to fix it.
1. Please check whether your BenQ Android TV dongle is QS01 or QS02.
2. If the dongle you have is QS01 or the BenQ projector you have is
W2710i/HT3560i or TK860i, please directly contact BenQ service
center in your area. If the dongle you have is QS02, please continue
the following steps.
3. Please remove the QS02 dongle from your projector and check if the
error remains or not. If it is gone, please directly contact BenQ.
If still remains, please continue the following steps.
4. Put the QS02 dongle back to the projector and turn on the projector
5. Press and hold the button (circled in red) with a paper clip to select and
operate try again, and release the button once the selection is changed
from blue to light green to restart QS02 dongle to fix the issue.
You would feel a click once you press the button.