When launching VideoStudio Pro X4, the error "load from stream error" will pop up on the screen preventing the application from loading; this could be due to corruption of the file library in VideoStudio.
Please close VideoStudio, go to Start Menu, andtype this on the search field (on Windows Vista/7) or Run command (on Windows XP): %appdata%
Hit the enter key to open the Application Folder. Inside the Application folder, go to Ulead Systems folder > Corel VideoStudio Pro folder and rename 14.0 folder."
When you launch VideoStudio again, it should launch correctly.