Invalid import file: no building modeler data

Designer 2.5
1

I was using the old free designer and have multiple exports from there. However, whenever I try to import any of them into 2.5 I get the following error:

Invalid import file: no building modeler data

Thanks for any help!

2

This is simple one to answer.

The zip file from the demo designer doesn't contain the building_modeler.xml file that Pro uses fit importing.