What are the PC's specs: CPU/GPU/RAM?
Back up your work. Save Project File AS routinely, giving it a unique # or name, so as not to overwrite prior saves. Using Save Project Files (no AS) will overwrite. From the HOME tab, that choice is available by clicking the caret to the right of the Save Project button on the toolbar.
Then close the program, relaunch it and go to OPTIONS | DISK tab. Clear Unused Cache Files.
VideoPad has been known to crash due to problems with older graphics card drivers. If you are experiencing frequent crashes then you should download and install the latest drivers for your graphics hardware and update to the latest version of DirectX.
AMD / ATI users: http://support.amd.com/us/gpudownload/Pages/index.aspx Intel users: https://downloadcenter.intel.com/default.aspx nVidia users: http://www.nvidia.com/Download/index.aspx?lang=en-us Update DirectX: http://support.microsoft.com/kb/179113
Yet another test you can make is to open OPTIONS | ADVANCED tab and in the bottom GPU Video Processor area click the caret and choose None | CPU only. 
Most problems are quickly addressed by working with folks here. To let them see what you see, take a few minutes to share the project.
Please follow the instructions in your other thread and we'll take a look. And install the latest 64-bit release if you haven't already.