Hi Ilke,
I would recommend you to:
1) copy the project folder from the USB to the path Documents\DHI\WEST\data\projects (i.e. where WEST projects are saved by default)
2) make sure that the project uses the right Block/Model Library. When opening a project with WEST (espeically if loaded from another folder than the default), you're asked to select the Block/Model library used in the project. You should therefore verify that the project uses the default library or a modified version of it - and choose accordingly.
BR