FYI, this issue has been resolved by the latest version of win-acme, 2.2.9.1. "This release changes the implementation of ARI (ACME Renewal Information) from the draft 1 to draft 3 of the specification, to remain compatible with the leading implementation in Boulder / Let's Encrypt. Previous win-acme releases from 2.2.3 to 2.2.8 are currently reporting non-fatal errors because draft 1 compatibility was dropped by Let's Encrypt"