The 3D viewer uses OpenGL technology to present the 3D scene. Unfortunately graphics card manufacturers give preference to implement DirectX (competing technology) on Windows, and their OpenGL drivers are often buggy. As we improve our 3D viewer and add new features, they might unlock a new bug in some graphics card drivers.
It usually helps. First you need to find the name of the graphics card (chip) used in your computer.
There are 3 major manufacturers of graphics cards: Intel, NVidia, AMD/ATI.
Now go to the respective manufacturer website, and download and install the latest driver for your graphics card.
If this fails, please report it to us, including the name of your graphics card.
If everything fails, you can use VRML plugin or present 3D in web browser instead of our internal 3D viewer.
You can install Cotrona 3D and select it as VRML plugin choice in Room Arranger
Explore in 3D - Setup window.
Another possibility is to install BS Contact and select to show 3D in web browser.
Another possibility is to downgrade to a previous version of Room Arranger. See older versions page and select a version with older 3D viewer (for example 7.2.7 or 7.4.3).