If you are planning to upgrade an infrastructure component (Cisco VCS, Acano MCU etc) or have already upgraded the component, check that the vendor for the component you are upgrading has not made any changes to TLS settings.
Changes to TLS settings may cause your infrastructure components to appear as down on the dashboard. If you where previously connecting with http, you may now have to change the connection properties to https.
Sometimes, you may also need to open port 443(https) on your Firewall to allow traffic for this component.