Export project generates empty wav file if the project has not been played once (audioContext needs to be resumed before export). Try to load a project and to export it right after it has been loaded : empty .wav file
Play it for a second and export it : correct .wav file generated.
Export project generates empty wav file if the project has not been played once (audioContext needs to be resumed before export). Try to load a project and to export it right after it has been loaded : empty .wav file Play it for a second and export it : correct .wav file generated.