I use an Arduino Mega for testing and that works fine.
I use Adafruit 5V Pro Trinkets for the actual evices I make and that has worked fine...up to now.
Suddenly, the serial port for a connected Pro Trinket is greyed out...on ALL my Pro Trinkets and I have about 20 of them. They worked yesterday. They do not work today.
I have reinstalled drivers and rebooted...all to no avail. Please, can anyone suggest a solution, this is driving me insane!