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If you are using an external Platform Services Controller (PSC), Single-Sign On (SSO) provider or have a custom SSO domain, toggle the Use Custom SSO Configuration switch to Yes.
a. Enter the PSC/SSO server IP address or fully-qualified domain name (FQDN).
b.If you are using the default PSC/SSO provider configuration, you do not need to complete the Advanced Options (optional) fields. Complete the SSO Admin URL, SSO STS URL and
Lookup Service URL only if you specified a custom configuration during the deployment of your PSC or SSO provider.
For additional details regarding your PSC/SSO provider configuration, please see the vCenter Server vpxd.cfg file.
In vCenter Server Appliance 6.x, the vpxd.cfg file is located at /etc/vmware-vpx/.
In Windows Server, the vpxd.cfg file is located at C:\ProgramData\VMware\VMwareVirtualCenter\vpxd.cfg.
In vCenter Server 6.0, the vpxd.cfg file is located at C:\ProgramData\VMware\vCenterServer\cfg\vmware-vpx.
Also check if we are able to reach the vCenter from the collector and if it is on a different site please deploy the collector on the same site.