I published this blog post in July 2015 and it is still relevant. The feedback for this blog post was incredible, and I’m not joking when I say: I saved many admins weekends. ;) It has shown, that this error still occurs with Exchange 2016 and even 2019. Maybe not because of the same, with Exchange 2013 CU6 fixed bug, but maybe for other reasons. And the solution below still applies to it.

Sometimes you have to replace SSL certificates instead of updating them, e.g. if you switch from a web server SSL certificate to a wildcard certificate. The latter was my job today. In my case, the SSL certificate was used in a Microsoft Exchange 2016 deployment, and the NetScaler configuration was using multiple virtual servers. I’m using this little script for my NetScaler/ Exchange deployments. [caption id=“attachment_3750” align=“alignnone” width=“640”] skylarvision/ pixabay.com/ Creative Commons CC0[/caption]

A few days ago, I ran into a very nasty problem. Fortunately, it was in my lab. Some months ago, I replaced the certificates of my vCenter Server Appliance (VCSA), and I’ve chosen to use the VMware Certificate Authority (VMCA) as a subordinate of my AD-based enterprise CA. The VMCA was used as intermediate CA. The certificates were replaced using the vSphere 6.0 Certificate Manager (/usr/lib/vmware-vmca/bin/certificate-manager), and I followed the instructions of KB2112016 (Configuring VMware vSphere 6.

Generating a certificate signing request (CSR) is the first step towards a signed certificate. The requests is generated with the applicants private key and consists of the public key, a name and optional attributes. To generate a CSR, you can use tools like OpenSSL on a Linux box, or sometimes the application itself can generate a CSR. But if you have a Windows box, you don’t have OpenSSL by default. And it’s unhandy to install something just for a single CSR.

I ran a couple of times in this error. After applying changes to SSL certificates (add, replace or delete a SSL certificate) and rebooting the server, the event log is flooded with events from source “HttpEvent” and event id 15021. The message says: An error occurred while using SSL configuration for endpoint 0.0.0.0:444. The error status code is contained within the returned data. If you try to access the Exchange Control Panel (ECP) or Outlook Web Access (OWA), you will get a blank website.