This is a rare issue and has been observed only once with SEE 11.3.
This is not expected behavior, however, contact Symantec Support if encountering this issue.
When making any changes to the Symantec Endpoint Encryption Configuration Manager on the SEE Management Server, the IIS binding for the certificate is removed. This means connections with SEE Clients will no longer work until this is resolved.
This issue has been observed in a production setting only once, and the cause of this issue is unknown. The workaround is specifically to go into IIS, and re-associate the certificate to IIS for that website.
To re-associate the certificate to the website:
1. Open IIS Manager
2. Expand the Sites and click on the "Symantec Endpoint Encryption Services" website
3. On the right side, click on "Bindings..."
4. Click on the "https" type, then click "Edit..."
5. Under the "SSL certificate" field, browse to the server certificate for your website associated to its FQDN, and click "OK".