1) Please ensure your computer meets the recommended specifications shown below: -
https://www.reallusion.com/iclone6/iclone_requirements.aspx
The default iClone 6 graphics mode selection is DirectX 11.
iClone 6 DirectX 11 requires an independent GPU with it's own video memory, ie, a Nvidia or an AMD graphics card that fully supports DirectX 11 and has at least 1GB of dedicated memory.
Please note for integrated graphic card, like Intel(R) HD Graphics is currently not able to support iClone 6 DirectX 11.
Whereas for iClone 6 DirectX 9 graphics mode selection, that is allow much lower hardware specification to run. Please note this would entail limitations of certain DirectX 11 related features like Displacement, Real-time Smoothing, SpeedTree, limited number of lighting, and partial Indigo support.
Version Comparisons: https://www.reallusion.com/iclone6/iclone_matrix.aspx
Related FAQ: How to switch between DirectX 9 and DirectX 11 Graphics Mode?
2) If you have already confirmed that your system meets the requirements, then please updating your graphics card driver to the latest available.
Nvidia: http://www.nvidia.com/Download/Find.aspx?lang=en-us
AMD: http://support.amd.com/en-us/download
3) Important: If your computer has switchable graphics, please do ensure you are running the iClone.exe found in the folder below with the more powerful graphics card (normally Nvidia or AMD). Do not choose the Intel graphics option.
C:\Program Files\Reallusion\iClone 6\Bin64
For more information on switchable graphics please check out the link below. This contains additional instructions on how to select the right graphics card option.
http://forum.reallusion.com/Topic212526-386-1.aspx
4) Please also run Windows Update to ensure your system is fully updated.
In Windows 7, clicking Start > All Programs > Windows Update > Check for updates.
In Windows 8, go to the Start screen and type Windows Update. Then select "Check for updates" from the search list.
In Windows 10, clicking Start button, then select Settings > Update & security > Windows Update > Check for updates.
5) If you still have problem in Windows 7, please have installed the latest Windows 7 SP1 updates: -
http://download.microsoft.com/download/F/4/3/F431C6D1-D581-459E-BB01-A6AEBBB779FC/Windows6.1-KB2670838-x64.msu
6) For issues where iClone 6 refuses to start but you don't get an "iClone initialization failed" error, please try right clicking the iClone 6 icon and choose "Run as Administrator".