Adding a user with providing access

So I have a bunch guest bloggers who have been writing posts for my website. I use a bio box plugin at the footer of each post to display info about each author.

I upload the post myself and create a new user for each blogger (then assign their bio info to their blog post before publishing). Up until now I have always created a new user, using the actual author’s email address, and checked a box that prevented them receiving the password. This has prevented anyone access my website.

However, for some reason that option is no more. It seems to have disappeared and the only option is to send them the password when I create the user –?regardless of the type of user.

Why is this and can anyone help!?