Your colleague send you Primavera XER file and Layout file. After you import project successfully, you click on Layout -> Open -> Import -> Select the layout. And this error appear:

You may think “Wow, this layout file must be damaged. I need to tell him to send me again”.

Wait! It’s not because of the Layout file. It’s because of you’re in the wrong window. After import project maybe you’re still in Project window.

You have to switch to Activities window. Then you can import layout successfully.

So, to import Activities layout, you need to go to Activities window.