Dear all, I´m using the most current version 60.5 of Thunderbird on a Server 2016 Standard for testing purposes. Before 60.5 was released, I was able to send digitally signed e-mails using a self-created certificate. With 60.5, Thunderbird says the certificate would either not be found or have been expired. When I check in the S/MIME settings, the certificate is present and valid until 2099. I exported and re-imported the certificate - no luck. I created a new one and imported it - no luck. The certificate has been created with Pluralsight SelfCert and, as I said, did work before 60.5. Is this a bug or am I doing anything wrong? Many thanks, Jens <img src="https://www.bildhost.com/images/2019/01/31/Error.jpg" alt="Error.jpg" border="0" /> <img src="https://www.bildhost.com/images/2019/01/31/Settings.jpg" alt="Settings.jpg" border="0" />