Problems with Shell Loads

Hello everybody,

I am new in this program and I have a question about an assignment I have to submit.

I need to include a "tensile edge load" in my abaqus model, but when I am doing it the next advice appears: "Region must containt only free edges" and I do not know from where the problem could come.

If it can help, the geometry has been exported from CATIA solid  as stp file and his features has been changed to shell.

Regards,