Do make sure your system is fully updated, especially the graphics drivers. Screen lockups can occur if you are using outdated graphics drivers or you have an unsupported graphics card. Do also ensure you have the latest version which is 8.03. You can get this from your Member Account if you are using a purchased version.
If you do still encounter problems after updating, please contact Technical Support using the link below and supply your full system specifications. They will then be able to check for any problems and advise you further.
http://www.reallusion.com/CustomerSupport/UserEx/QForm.aspx
Peter
Forum Administrator
www.reallusion.com