When you turn on Sun shadow for the 3D view, 3D may stop working on some Intel graphics cards with some driver versions.
Workaround:
If you have Dell computer and you install 64-bit version of Room Arranger, it might crash when showing Project - Open and Project - Save As… dialog window. It is probably caused by Dell Recovery & Backup shell extension, as described here: QTBUG-41416.
Workaround: