Thanks for the prompt responses. I connected my monitor and rebooted the Pi to verify that it was the same error message I was getting. Naturally, I suddenly can't reproduce it. Oh well. I did change my config settings to run headless (/boot/config.ext and raspi-config resolution), so maybe that had something to do with the error message.
I've got two more questions while I'm here:
1. I've installed the OS several times now (3-4) because I was troubleshooting the most efficient way to go from nothing to a totally-functional, headless RPi4. I was writing a tutorial. This last time I did so, I find that if I spend too long in the PnCConfig application (say, 5 minutes) it will kick me out. It appears as though the application is faulting with no warning. I had to fly through the configuration to get it to work. My next troubleshooting step is going to be to just install the OS again and give it another shot -- I don't think I had this issue on my first install. Any ideas?
Which brings me to my second question:
2. I'm running my RPi4 on a MicroSD card. Some online research suggests that the device will perform much better with a good external SSD; however, that same research concludes that the USB port shares traffic in some way with the Ethernet port, whereas the MicroSD card does not. It sounds like a tradeoff... better overall performance of the Pi, or better Ethernet performance. I'm using it with a Mesa 7I76E -- could you folks share your thoughts?
