Under normal circumstances, there will be no situation in which the health code cannot be opened. If the health code cannot be opened, there are several reasons to consider:
1. If the mobile phone has no network, you can turn on the traffic or connect to the wireless network, and then the health code can be turned on normally.
2. If too many people use the health code and the system crashes, you can re-enter it later. If you can't open it all the time, you can explain it to the staff when you go in and out, and take the feedback from the staff as the actual operation.