Thanks for your reply and link to the Wise Geek article. I like his articles, and I hadn't seen that one before.
I'm not experiencing any problems outside Event Viewer... Yes, I realize many of the errors and warnings in the Event Viewer can be safely ignored; basically every computer that has been running for any length of time will have some errors and warnings in the log.
That said, I do periodically check the Event Log, and I try to research and address errors and warnings even when I'm not experiencing any problems with the OS. I try to minimize the errors and warnings, not that it makes any perceptible difference in the computer's operation and performance. I assume a computer with less errors and warnings is running more smoothly than one with more, and I generally learn something while I research the errors.
In this case, I found an article addressing "The driver \Driver\WudfRd failed to load", and it appears to be somewhat reasonable.
It offers 6 methods to address "The driver \Driver\WudfRd failed to load". I had already checked / tried methods 1 thru 5 on my own. Therefore, I wanted to see if Method 6: "Check Windows Driver Foundation service Settings" would help.
More concerning now is the fact that "Windows Driver Foundation - User-mode Driver Framework" is missing. I believe it is one of the standard services in Windows 10. I don't recall having deleted the service. I don't think I've deleted any Windows service... So in this case, Event ID 219 is not associated with any problem I'm experiencing, but it did lead me to a concern: I'm Windows 10 install is missing a standard service for some reason.
That's my understanding.