InfoPath Dev

I am trying to add another person/group picker but get the error that it cannot be bound to the field that I have selected. I have tried all types of fields and all fields that I have in my form?

what have I done wrong? Is it not possible to add multiple people picker fields in one form?

Please help!

What type of form is this? Is it by chance a SharePoint list form?

yes it is

You probably have one column in the SharePoint list. You can't just add controls to this form. You have to first add the columns in the SharePoint list, then design the form.