People Picker Browse Button

Hi,

 I have a People Picker column, where user can be selected only from a specific SharePoint group. The SP oob version of the control show a browse button where user can see the available choices, Using Nintex Forms 2013, this button isn't present and I'd like to bring it back, otherwise a user cannot know how to correctly fill the field.

 Is there a known way to bring the button back?

I've seen that for NF2010 the last post of this thread (http://connect.nintex.com/forums/thread/32441.aspx ) shows a way to use the old people picker control, I've tried to use it in NF2013 but this method errors with the following alert:

• Could not load type 'Nintex.Forms.SharePoint.FormControls.PeoplePickerFormControlV1' from assembly 'Nintex.Forms, Version=1.0.0.0, Culture=neutral, PublicKeyToken=c52d764dcf7ec883'.

Thanks to all!

 Giacomo Gelosi