This error can have multiple reasons and solutions, depending on when it happens.
This crash usually relates to a rights/permission issue or the license service on Windows Vista, 7 or 8. Please try to start coDiagnostiX with Administator Rights using a right click on a shortcut.
If it works this way, there's a good chance the crash is caused by a missing license service. Please try to restart or reinstall the license service to fix the problem.
See this page for info: How to install the license service