I had a problem printing 1099-NEC as well. I was able to print 1099-MISC. The rep I had at Quickbooks was able to isolate and solve the problem. She had me run a back up of my QB file, then:
Click HELP
Click Update QB Desktop
Click Update Now folder (not the blue box)
Click Reset Update box
Click Get Updates
I then had to close QB and re-open it.
I am now busily printing 1099-NEC for each of my clients.
