Hello @CanyonMan,
Seems a bug of your letenscrypt-win-simple client, other people is having issues renewing their certs https://github.com/Lone-Coder/letsencrypt-win-simple/issues/308 so maybe you could get more help posting your issue on github page.
I don’t use Windows so I can’t recommend any alternative to letsencrypt-win-simple but you could check the list of Windows clients, maybe other could fit your needs better than the current one
Cheers,
sahsanu