This means that the HCX Manager where you are seeing the error message is unable to communicate with HCX cloud services. Check proxy and internet connectivity from the manager.

https://docs.vmware.com/en/VMware-HCX/4.7/hcx-user-guide/GUID-920242B3-71A3-4B24-9ACF-B20345244AB2.h...

If that doesn't resolve it, then raise an SR.