VM settings can not be edited on vSphere UI, error - Error Loading Data, noPermission

Products

• VMware vCenter Server

Issue/Introduction

• The vSphere UI responsiveness is slower than expected
• VM settings are unable to be edited in the vSphere UI, when trying to do so and error is presented - Error Loading Data, noPermission
• It is not possible to open a VM web console session in the vSphere UI
• The /var/log/vmware/vpxd/vpxd.log contains the error below - 

Out of HTTP sessions: Limited to 3000

Refresh function is not configured. User data can't be added to scheduler

User name: VSPHERE.LOCAL machine-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

Environment

VCF 9.0.0.0

Cause

• The user machine-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx is consuming many HTTP sessions, pushing the total used to over the HTTP session limit.
• As a result vSphere UI performance and functionality is affected.

Resolution

• Restart all services on the vCenter -

service-control --stop --all && service-control --start --all

• The issue is then expected to be resolved.