There are two problems that can arise in opening the padlocks:

1.    The Master Lock app does not show the padlock as “awake” even when the padlock light is on. This is a problem with the Master Lock app. The solution is to fully close the app and then re-start it.

2.    The Master Lock app shows the that lock is unlocked and the padlock light is green, but you can’t open it. This happens sometimes, with some locks. Please let me know when it happens. The solution is simply to keep trying. I’ve never had a lock just fail to unlock, but it may take 5 tries before it works.