I noticed this with one of my 3210-L outlet/Z-Wave repeaters some time ago; it doesn't seem to cause any harm. In my case it was caused by a scheduled refresh job which was showing on the device settings page for the Z-Wave repeater device for which the message is logged (the scheduled jobs are shown at the bottom of the settings page).
Not really sure how it got there; I believe it resulted from changing its device driver (even when changed back to the generic driver, the scheduled job sticks around). From forum browsing I learned that the way to get rid of it is to run code to unschedule it; I temporarily installed a modified device driver (edited and installed a copy of SRWhite's [RELEASE] Iris SmartPlug Z-Wave Repeater (3210-L + others) )by finding and changing the 'schedule()' statement to 'unschedule()' then switching back to the Generic Z-Wave repeater driver. At least that is my recollection...
