I was changing the drain plug mechanism in my bathroom sink, as a precaution, I turned the water off at the wall, under the sink. After fixing the drain plug and turning the water back on, I get no water out of the faucet. It is puzzling because the only thing I did that should have anything to do with the water was turn the knobs to the "off" position, then, back to the "on" position. Besides that, I made no changes to anything other than the drain plug hardware. 100% sure the water was working before this. Help!

Never mind. Figured it out. The faucet screen was clogged. :)

Hi kelldog and welcome to The Plumbing Page at AMHD.Hi and welcome to The Plumbing Page at AMHD.

What happened is that when you turned off the water, (and you didn't need to to work on the pop-up ) you disturbed minerals built up in the pipe walls that clogged your aerator .
Glad you're all fixed up now. Regards, Tom