vCenter login fails with error: The authentication server returned an unexpected error: ns0:RequestFailed

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• You cannot log in to the vSphere Web Client
• Logging in to the vSphere Web Client fails with this error:

A server error occurred.
The authentication server returned an unexpected error: ns0:RequestFailed: EndTime: Tue Jun 09 06:12:29 MST 2020 is not after startTime: Tue Jun 09 06:13:14 MST 2020. The error may be caused by a malfunctioning identity source.
Check the vSphere Web Client server logs for details.

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Environment

VMware vCenter Server 6.x

Cause

The time difference between the vCenter server and its PSC is more than 1 minute, which is causing login error.

Resolution

Correct the time by syncing the time to a NTP server.

Workaround:

To work around this issue, place the vCenter Server and the PSC on the same ESXi host and synchronize the time directly with the host.