Sometimes your 2nd generation (BioStation 2, L2, A2, W2) slave device might not operate properly (not responding to zone action or refusing all authentication).
In that case first check if the device is disconnected.
Unlike 1st generation devices, the disconnected sign (red icon) may not appear and the configuration items might not be grayed out.
Check if your slave device is appearing as below:
Time: shows as UTC - 0 (W. Europe Standard Time...)
Operation Mode: everything appears as No Time
This means your slave device is disconnected. You can double check by trying to apply a setting. It will fail to save.
Check your wiring and device power to see that your device is connected correctly.
After confirming that the wiring and power is correctly installed, reconnect the master device.
If you click on your slave device you will see that it will now load the correct operation modes and values.