There could be a possibility that the keypad lost cellular connection for some reason. Do the following:
1. Unplug the power source to the keypad and leave it unplugged for one minute.
2. Plug it back in and do not touch the keypad for 3 minutes. Let it re-boot completely.
3. Try a good code once again. (Make sure the tenant code you are trying has a zero balance in management software)
4. If that doesn't correct it, please call our customer service department.