You may see vpxd.stats.maxQueryMetrics relevant error when retrieving performance data of ESXi hosts, virtual machines, or other entities on vCenter Server by PowerCLI. The full error message:
This operation is restricted by the administrator – ‘vpxd.stats.maxQueryMetrics’. Contact your system administrator
VMware published a KB about how to fix that. Please notice that the mentioned vCenter advanced parameter config.vpxd.stats.maxQueryMetrics is case-sensitive.
202203 Update:
The parameter is removed in vCenter Advanced Settings after upgrading to vCenter Server 7.x. You have to reconfigure it.