In vSphere Web Client, the Client Integration Access Control dialog box might be enabled or disabled based on the user preferences selected. The dialog box is disabled when the Always ask before allowing this site check box is not selected; and the Allow or Deny options are selected for the source.
You can clear the existing user preferences manually by following the steps below.
"auth":
{
"https:\/\/km-cpd-gen-228-dhcp71.eng.vmware.com": "true"
}