For vSphere Web Client 5.5, 6.0, 6.5, 6.7 follow "Could not connect to one or more vCenter Server Systems: https://vCenterFQDN: 443/sdk" error in the vSphere Web Client (2050273)
After installing or upgrading to the vSphere Web Client 5.1, you experience these symptoms:
To resolve this issue, remove the file containing left-over SSL thumbprint file, so that the vSphere Web Client is forced to use the new SSL Thumbprint.
To remove the file containing left-over SSL thumbprint file: