I've been using my ISY exclusively with Insteon devices for probably 6+ years and have just over 50 switches, etc. - all working great. I added a Schlage Z-Wave lock about a year ago without issue, but I'm now trying to add a Leviton plug-in dimmer (DZPD3) and my ISY just isn't finding it. Although my ISY is running v4.9 I've never upgraded my Z-Wave module firmware. I'm now wondering if this is preventing it from finding this newer device. Distance between the ISY and Leviton is about 12 ft. My current version info for everything is below. Would updating the Z-Wave firmware likely improve this and if so what is that process?

Thanks in advance.

You'd need to upgrade your Isy firmware to 5.0.16c to use that device. Make sure you read the full instructions should you decide to upgrade before starting to avoid any issues

I wrote following conservative guide to move from 4.x to 5.x

https://forum.universal-devices.com/topic/26381-upgrade-from-473-to-5015a-task-list/

Thanks to both for the responses and the link. I’ve been putting this off but seems it’s time to give the upgrade a go. Do I need to upgrade to 5.0.16c first or can I go straight to the latest firmware version?

It looks like 5.0.16c is as high as I can go until I replace my current z-wave module. 

It looks like 5.0.16c is as high as I can go until I replace my current z-wave module. 

You are correct.