No rig available in "Imbed Eleven Settings" dialogue of I/O page

[oldjohn]

I cannot imbed rig settings to guitar tracks.
I cannot use settings imbedded in clips to control Eleven Rack (right click on a clip, choose "Load Guitar Rig settings" and nothing happens at my Eleven Rack)
I used to be able to imbed.
Screenshot of I/O page attached.

Windows 10 Home 64 bit.
8G Ram, i7-4700 processor, dual hard drive HP laptop
Eleven Rack connected directly to laptop USB 3.0 port
Eleven Rack driver and firmware up to date
Pro Tools 11.3.1
Eleven Rack is listed as peripheral
Eleven Rig L/R listed in I/O paths, along with Line L/R, Guitar in/Mic In and Digital L/R

I have uninstalled and reinstalled PT 11.3.1 and Eleven Rack. Many reboots. Connected Eleven to a different USB port, then deleted phantom racks and ports in Device Manager. I went to each tab in the I/O page and selected default. I have loaded old sessions where the imbed worked and now it doesn't. I have created new, blank sessions after reboot and launch of PT and problem persists.

I have researched similar problems, but none that I found match this exactly.

Thanks in advance for any help you can offer.

[oldjohn]

Fixed by checking Eleven Rack in MIDI Input devices. Who knows how it became "unchecked"?