Looks like I'm not the only one who came looking for an answer to the UAC error. I was happy to find an article which said the problem had been solved. Nope. Why is it labeled as such?

I feel like I should reply and let others know how I was able to get the scheduled reports to work. I began to think that there must be another way to turn UAC off, other than the Control Panel method. A simple search led me to a website which lists four methods for turning off UAC. I'll list it here. 

https://www.minitool.com/news/how-to-disable-uac-windows-10-004.html 

I used Option 3: Disable UAC Group Policy, which did the trick. After a reboot, I no longer received the error upon opening the Scheduled Report Center. I'm guessing the Control Panel method didn't turn UAC completely off? Anyway, I hope this solution works and helps someone!