Problem with Import Shape Polygon

We try to import a Polygon-Shape. It´s 2D and it´s a Polygon. But always we get the same error: (625 Bytes)
Does anyone know the solution to the problem? Thanks!

Hallo @boris.huettenhofer,

Welcome to the Pix4D Community :handshake: .

This behavior is expected. In order to compute a volume, PIX4Dmapper needs to know the amount of the DSM that is located above or below the base volume. Therefore the volume shapefile polygon must contain a 3D surface.

You can learn more here: