When I import a STEP file PCB assembly several components disappear when I save it. Also it complains of empty sketches, dozens of them, asking me to delete them during the save.

If I choose 'Yes' and delete them some parts are missing.

Should I choose 'No', and save the assembly without deleting the empty sketches, virtually the all the parts disappear.

If I open the STEP in E-Drawing no problems are seen. Every part is visible.