this probably means that Unity Failed to initialize Unity graphics
This issue occurs when 3d Acceleration is not enabled. You can see this if you type "dxdiag" in Start > Run and check Display. All three options should be enabled. To make sure this is the issue also check the editor.log. It can be found in C:\Users(username)\AppData\Local\Unity\Editor. Keep in mind that AppData is a hidden folder so you need to enable “Show hidden files” from the Folder Options.
The error you can see in the editor.log or editor-prev.log is:
“d3d: no support for this device type (accelerated/ref)
Failed to initialize Direct3D 9.
Make sure you have DirectX 9.0c installed, have drivers for your
graphics card and have not disabled 3D acceleration
in display settings.
Failed to initialize unity graphics.”
How to fix it :
enable 3D Acceleration either from Dxdiag, Nvidia Control Panel ( for Nvidia GPUs) or from Catalyst ( AMD GPUs)
update the graphic card drivers
start Unity in OpenGL mode by using -force-opengl command. Instructions here http://docs.unity3d.com/Documentatio...Arguments.html.
reinstall DirectX, instructions here : http://support.microsoft.com/kb/179113