Yes, it's known that Camtasia is somehow unstable. Even if the latest version is installed, most users will have issues with it because of various reasons. Mine crashed continuously because the XviD codec that I used, had wrong parameters and wasn't updated to the latest version. However, always use the Check for Updates because this way you will have the latest version installed and your bug might be fixed with a new installation.
To check for updates go to Help > Check for updates. Make sure you are connected to the Internet before activating this function.