Non-repeating groups are not supported as form library column names

I created a custom Infopath form and I added PERSON/GROUP PICKER to my form. It added person object to myFields with that control.

I want to publish it to Sharepoint Server. I did these processes : File -> Publish -> Sharepoint Server -> I entered site's location and clicked NEXT -> Form Library -> Create a new form library -> I entered new library's name. I am on columns screen on publishing wizard. I clicked Add column button and selected Person object from myFields and clicked to OK. But it didn't add my person column. The message is :

How can I associate this form item with Sharepoint library?

Note : I want to add multiple users from my form.

Thanks