I recently observed that my hub was experiencing excessive load. Upon checking my logs, I noticed that one switch (Inovelli Dimmer 2-in-1 Red Series VZW31-SN) is displaying the error 'hexBinary needs to be even-length: 9F0302delay 500' over and over each time the switch is initialized, see screenshot below. This is the only Inovelli switch that I have on my ZWave network. I have reached out to Inovelli and worked with their tech support to try a number of things. Below is everything that I have attempted, but none of these steps have resolved this error. Please let me know how to resolve this. Thank you for your help!
Updated the firmware on the switch from version 1.03 to 1.04 using the Hubitat Firmware Update tool.
Ensured that I am running the most up-to-date Inovelli community driver for this switch by updating the driver using Hubitat Package Manager (dated 2025-11-20)
Ensured that my C-8 is up to date
Removed all Rule Machine rules that included this switch
Excluded the switch from my hub, rebooted the hub, and re-paired the switch into my ZWave network using the security option.
The Inovelli tech says that he is running many of this type of switch across all of his Hubitat hubs (C-7, C-8, and C-8 Pro) and that he does not have this error in his log. I confirmed that he is running the same firmware versions as I am on his switches, Hubitat hub, and device driver. He has run out of ideas for me to try, which is why I turned to the community.
Thanks a lot for your reply. The problem is that the device works fine. There is no device or app to troubleshoot. After about a week of uptime, my hub alerts of excessive load and when I look at the device stats, this switch is consuming the most resources on the hub. The error in the screenshot seems to indicate that there is a coding error in the device driver, or in the Hubitat firmware. When I reached out to Inovelli, their support said that they aren’t able to replicate this error.
It would be nice if Hubitat support would respond to this thread.
Since you're on a C-8, I assume you're running legacy Z-Wave, but if you happen to know or can verify that you don't see a "Switch to Legacy Z-Wave" button in Settings > Z-Wave Details, that would confirm.
Also in Settings > Z-Wave Details, what do you see under the Security column for this device?
With all logging enabled in their driver (debug logging is conventionally what you need, but their custom drivers don't tend to follow Hubitat convention), what additional log entries do you see before the errors?
Thanks!
EDIT: A quick look at the error combined with their code suggests somewhere they are trying to run zwaveSecureEncap() on a "command" like "delay 500". This is likely from them iterating over a list of commands that are returned by a method like refresh() or ledEffectOne() in initialize() (where I looked based on the fact that this is what you noticed; there could be other places), where these methods return a list that had already delayBetween() run on it, causing this invalid input to be fed into zwaveSecureEncap() (which looks like it was already run on the list, too, and running that twice on the same command might actually not work either -- but it would definitely throw an error on the delays, which appears to be what you're seeing).
The other logs prior we all the logs for when the switch was added to my zwave network and all the parameters were set. The error logs stopped maybe 30mins later?
I meant other logs around the time of the error if you have all logging enabled in Inovelli's driver, as it looks like they should log the specific commands that were constructed in at least some driver methods (which are not in your logs above).
But I'm not sure there's any need at this point -- I think the problem is the one I identified above, which they'd need to address in the driver. You'll only see it if you're using security and only if you're on legacy Z-Wave, so perhaps their test environment is different.
Thanks a lot for the assistance! I checked the areas that you requested.
I do not have a "Switch to Legacy Z-Wave" option in my Settings > Z-Wave Details page.
The Security column for this device lists "S2 Authenticated". It also has a direct connection from the hub (they are very close) at 100kbps (if that helps).
I took screenshots of my logs before turning on debug logging and again afterwards and rebooting my hub, since this issue seems to be triggered by the initialization routine. I also took a screenshot of my device statistics, which shows that after 3 days of uptime, this switch is consuming 17% of my hub's resources and has over 3K states. Could this be caused by the code error as well?
Before enabling debug logging and rebooting the hub
Yeah, the very last (reading top down, or first chronologically) log entry in your second screenshot, the one at 09:49:43.307 AM, has the key: they're apparently trying to run zwaveSecureEncap() on a list of commands that has both already had this method and delayBetween() (or perhaps manually inserted delays) run on it. The zwaveSecureEncap() method is barfing on the "delay"s, but I'm not sure it would like to be run twice on the same actual Z-Wave command either (I don't know; it may or may not work -- the delays are just the problem that is apparent from the logs). They need to figure out a way to stop this from happening in their driver -- confirming my guess above.
Hopefully that's enough to help them figure something out!
@MD617 I recommend matching the device drivers using Hubitat Package Manager, if you haven't done so already, and updating to the latest driver for the switch.
