After not working for a week and with only 2 days left in the trial, Native started working again?! I clicked on the plugin in Reaper and was prompted for a password. Now it works as if nothing happened. I tried it in Tracktion, and the Native plugin opened up with no problem.
I did install the most recent Windows 10 updates, but that was several days ago. I tried using Native without luck after that.
Kind of made for a less than optimal trial experience. :-(