I see from your posts while I was testing that Werner has found much the same on 12.04 as I did on Kubuntu 14.04.
wmayer wrote:OK, here is a way to reproduce the problem reliably:
* create a document and add a box to it
* switch to Drawing workbench, add a drawing and insert the box into it
* while the SVG view is active you can close the 3d view
* go to View > Create new view and from now on the rendering is broken
In this case even the above workaround doesn't work any more. And if you create a further 3d view and switch between the tabs then FreeCAD may even crash (somewhere deep inside the graphic driver).
When I try the above, the cube in effect goes into shaded mode, i.e. the edges disappear. If I go to wireframe mode the cube disappears.
However if you create a new Part primitive, e.g. a Part Cylinder or another Part Cube, ....the new primitive does display correctly...although the first cube remains incorrectly displayed.
OS: Ubuntu 14.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.15.4368 (Git)
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.7.1.oce-0.17-dev