Recently had to regenerate the SSL certificates on my vCenter Server Appliance as I had noticed they were originally created with localhost.localdom as the DNS name.

Quite easy to regenerate the SSL certs, just log onto the admin page of the vCSA (http://ip-address:5480) and log in as root. Click on the Admin tab and by Certificate regeneration enabled select Yes.
When you next reboot the vCSA, the SSL certs will be regenerated – just be sure to change it back to No after it’s complete otherwise it will regenerate a new certificate every time you reboot!

A problem I discovered after regenerating the SSL certificate of my vCSA was that I could no longer connect to Site Recovery Manager using vSphere Client.
It would try to connect and then fail with a Connection Error.

As I knew this was working prior to regenerating the SSL certificate, I guessed that SRM was still trying to authenticate with the vCenter Server using the old SSL certificate.

Checking through the SRM logs (\ProgramData\VMware\VMware vCenter Site Recovery Manager\Logs\) confirmed that my assumption was correct:

The SRM logs show a certificate error:
Failed to connect: std::exception 'class Vmacore::Ssl::SSLVerifyException' "SSL Exception: Verification parameters:
.......
The remote host certificate has these problems:
.......

Quickest way I could think of in order to solve my issue was to modify the installation of SRM to update the certificates.
Log into the SRM server, open up Programs and Features from the Windows Control Panel. Select the entry for VMware vCenter Site Recovery Manager and click Change.
At the SRM wizard, select Modify.

You won’t be able to change the vCenter Server details but you will be able to change the authentication method. Regenerate the certificate by selecting Automatically generate certificate.
Ensure you select Use existing database, otherwise you will lose all your protection groups and recovery plans.

Once the SRM installer was finished, I was able to reconnect to SRM using vSphere client.