VM console screen is black after vCenter is restored from backup

Products

• VMware vCenter Server

Issue/Introduction

• vCenter is restored, hosts and VM's show connected but VM console is black.
• VM backups are failing.
• VM's are responding to PING.

Environment

• vCenter 8.x
• vCenter 7.x

Cause

Hosts are not connected to the vCenter after restoration.  

Resolution

1. Disconnect host.
2. Reconnect host.
3. Verify VM console functionality.