Sectigo, an SSL Certificate Authority, has a root certificate that is due to expire on Saturday, May 30, 2020. The University of Pennsylvania is a client of Sectigo through the Internet2 InCommon certificate service and has been using that service for SSL/TLS certificates for several years.
Sectigo has a Knowledge Base article about this change that includes a list of browsers that have the required updates, additional technical explanations and details, and FAQs.
According to Sectigo, no action is required for most use cases. All modern clients and operating systems have the newer, modern USERTrust root, which does not expire in May 2020. For modern browsers, no errors should occur. Non-browser relying parties are the most at-risk, such as Java (prior to JRE 8u51), LDAP, and other non-browser clients. The required action for these is to confirm that the necessary trust anchors are available to these clients.
For additional information and instructions for checking non-browser clients, please visit https://www.isc.upenn.edu/news-announcements/incommon-certificate-service-sectigo-root-certificate-expiry
If you have any questions or concerns, please contact Client Care online at http://supportcenter.upenn.edu, by email at help@isc.upenn.edu, or by phone at 215-898-1000. Thank you for your help with the process.