Problem 1: The service does not start and you will see the error "A Specified Logon Session Does Not Exist. It may already have been terminated." in the windows event log or MailStore debug log.

Problem 2: The SSL/X509 certificate cannot be selected in the MailStore Server Service Configuration because it is not shown at all.

Solution: This indicates a problem with the certificate that should be used. Sometimes the matching private key cannot be found and the certificate cannot be used by MailStore.

First you have to get the subjects, serialnumbers and fingerprints of the installed certificates to identify which certificate is used by MailStore. Open an elevated PowerShell and enter the following command:

Get-ChildItem Cert:\LocalMachine\My | select Subject, Serialnumber, Thumbprint, HasPrivateKey

Then you can try to repair the certificate store with the following command

certutil -repairstore my SerialNumber

where SerialNumber is the serial number of the certificate that should be used.

Verify that the service is starting successfully now.

When this does not resolve the issue, you have to import the certificate again or you have to use the MailStore Server Service Configuration to create a new certificate. Make sure that the certificate is being imported in the computer's personal certificate store and that the certificate file includes the private key.

Article-ID: KB20150325-1-EN (Deutsche Version)