How do I update the certificate in Provision/vWorkspace V5.6.4.55

I'm on site with a customer who is upgrading their Provision systems to vWorkspace. However, in the last few days, one of their Provision systems started giving connection errors. When the users log into the Provision web portal, they have a button which they can use to change their Windows password. This button now gives the error "Connection failed (12175)" when the users enters his information and presses the "Change Password" button.

I've found on the Provision app server that a certificate is installed but recently expired. I have thus organised a replacement certificate and installed it into that computer's local repository but the error continues to happen. Can anyone suggest what I need to do to get the function working?