Hello,
I have downloaded a .rar file from NXP company. It contains two .dxf file. But I do not know why it gives a couple of warning. I have uploaded the zip file here in the attachment and I will show you the picture of the warning.
Don't think that you can import a PCB drawing to an EM simulator without specifically extracting the intended data. In case of doubt, it should be edited in a dxf tool before.
In AWR right click on EM Structure/Import DXF..., point to the DXF file you want to use, and then Select a Simulator (which you want and is available).