Catprincess - I was able to resolve the problem prior to reading your reply, but thanks for the info. After I had posted this I discovered I couldn't download any files from the web - tried to download a pic from my Yahoo mail and it gave me the same access denied error. I did a little testing, shutting down MalwareBytes, then MS Defender, then OA 188.8.131.527 and it turns out OA was causing the problem. With it off, I was able to download and install 184.108.40.2065 and I'm back in business. Thanks!
I, too have been getting the "HTTP/1.1.502 Bad Gateway" errors from automatic updates (OA Free 220.127.116.11.97). I'm running Windows XP SP3 with the latest updates. But when I try to download the latest version of OA, the download gets to 99% completion then fails with the error that "C:\ is not accessible" because "access is denied." I'm logged in with same local administrator account that I've used for years (and can perform other admin functions locally), and I've been using OA since Tall Emu days. I've tried downloading to multiple locations on the C:\ drive, to an external HD and to a USB