I think I’m in trouble, hoping for some help here. I installed KSC12 and installed a Sectigo certificate a good while back ( a year or so). All has been working great up until yesterday where I started getting an error when opening the KSC Console “Invalid Administration Server Certificate File”. After some troubleshooting, I found that when I change the date back to 29 May on the server, the KSC console launches just fine. If I set the date to 30 May or beyond, I get the error. Turns out that effin Sectigo have been issuing certificates using AddTrust External CA Root which coincidently expired 30 May 2020 (https://thesslonline.com/blog/sectigo-addtrust-external-ca-root-expiring-may-30-2020). Why on earth they would issue certificates using that CA for certificates with a validity date beyond 30 May 2020 is a MYSTERY to me to say the least… My actual certificate is valid until 21 April 2021. Biggest problem is that even if I change the date back on the KSC server to 29 May and I can get into the KSC console, all the clients are apparently not connecting to KSC. I have 250 machines installed in worldwide locations and don’t have access to most of them physically. Is there anything I can do to get the clients back on KSC, or is it a total loss?