Unable to change Domain field when logging into VMware Horizon View with factor authentication enabled

Problem

You’re attempting to log into VMware Horizon View where 2 factor authentication is enabled and you use your email address or UPN as the User name:

However, you notice that you are unable to change the Domain field as the drop down box is greyed out and locked:

Solution

I am unsure as to whether this problem is specific to the SecurEnvoy 2 factor authentication software this environment had but a way to get around this is to use the format domain\username for the User name field instead:

Using this login format will unlock the domain drop down box so you can now select the domain: