Inkscape sometimes opens the “Documents Properties” window outside the visible area of the desktop on Windows.

If this happens:

• Press Conntrol+Shift+D and then ALT+space to open the context menu of the “Documents Properties” Window
• Use the “arrow down” key once, to select “move” from the context meneu
• Hit “Enter” once
• Now use your arrow keys to move the window. It should snap into the visible area.

This solution works for Windows only.