I have received an exported VR project. When I open it, all the assets are missing.

After downloading the export ZIP file, please move it to a place where it can be stored long-term (e.g. a special folder on your laptop) and then unzip it. Unzipping creates the media paths for all graphics and assets used in the project, which means that if the files or folder are moved later, the VRdirect Studio can no longer find the file paths of the assets. The Studio then reports "File could not be found". 
Only if it is a ZIP file does the project have indirect media paths and can be moved. It is therefore advisable to first select a suitable storage location and then unpack the file.