Z-wave details from Settings > Z-Wave details.
I also have one ZEN51, installed for quite a long time and never had an issue.
Is it paired with S2 security or None?
Also, your product info is missing from the data section, resulting in my driver not detecting what device you have, so all the settings are probably hidden from you.
You can use this tool: [RELEASE] Z-Wave Universal Device Scanner to get those details back. Just press the "Get Info" command button, give it sa few seconds and refresh the page. Should then show the device ID and such below. You do not need to click any of the other buttons on the driver.
Switch back to the ZEN51 driver and run a configure and refresh the page again, should restore all the settings.