ZW-TX-FAILED

[KSchex]

I have a simple set of programs that sends either an on or off to an Inovelli On/Off Smart Plug when a button on my Aeotec Wallmote quad is pressed.  I get the following error message in the event viewer:

Aeotec Wallmote key pressed and released:

      Fri 10/12/2018 12:25:11 PM : [ZW023_201N001]      DON   0
      Fri 10/12/2018 12:25:11 PM : [ZW023_001_119]       ST 100 (uom=51 prec=0)

      Fri 10/12/2018 12:25:14 PM : [ZW-TX-FAILED] enc=Fail uid=21.0 cmd=0x25.02 SWITCH_BINARY

Inovelli On/Off Smart Plug commanded:
Fri 10/12/2018 12:25:14 PM : [     ZW021_1]       ST   0 (uom=78 prec=0)

If I break the program into two pieces, running them separately I do not get an error.  Not sure what exactly this error means.  Any help or pointers or direction into specific error code discussions would be appreciated.  Thanks very much.