I have one member of a board stuck on Virtual.

[Polly Maria Bond]

I have one member of a board stuck on Virtual on the free version he is the 4th member and he has signed in. It still will not allow him to see or comment. 

It will not let me change him over as he it says he has to log in however he has tried on several occasions. 

Can I duplicate the board and try again,

how can he be denied access still please? 

[Michael Pryor]

You have to invite the email address of the account he signed up with. That virtual user is not his account. 

Let me give an example to demonstrate:

1. You invite bobsmith@gmail.com to your board. This account doesn’t have a trello account. We add a “virtual” user to your board for that account. 
2. they sign up for trello but use bob.smith@gmail.com (note the period)

3. they have a trello account but that account does not have access to your board because it’s a different email than the one you invite.