The %age pint where it crashes is directly related to the place in the vsp: if it crashes at 50%, then half way thru you vsp there is something (a filter, effect, maybe a video clip with an odd frame rate or different resolution (Vs will match the 1st clip of the vsp, but not ones you have introduced later in the project file). Smart render has also been known to cause an issue, so try a render with this feature off. A same format render (all clips are the same format as the intended output) and you have smart render on may be the exception. So, rendering your 21minute vsp will probably take around 30minutes. As a rule of thumb, rendering will take at least as long as the video file composition, and probably longer depending on the file format (eg FHD) and what effects etc you have used.
A render will take longer in this mode but any issue will be VS. To isolate the issue to just the VS software, disable all acceleration in the preferences setting.
I tracked it to the Intel driver for the display chipset, which apparently has a bug intel will not fix because at 5years it's too old.
Example I have a core i3 Intel cpu, using the on-board display adapter, and hardware acceleration simply does not work in 2 video editors, but accel disabled with software only, both render fine. Disable the acceleration is the most direct way of isolating it.
It could be the video processor on the main chip (intel), the driver for it, the display adapter if you have one or the drivers for the adapters. 2020.02.Hardware acceleration is a known problem: it works on some systems and not others, generally related to the hardware or relevant drivers.2019.02.12 : Corel VideoStudio Pro 2019 : Adds Color Grading, Morph Transitions, MultiCam Capture Lite.2018.02.13 : Corel VideoStudio Pro 2018 : Adds Split Screen Video, Lens Correction, 3D Title Editor.2017.02.15 : Corel VideoStudio Pro X10 : Adds Mask Creator, Track Transparency, 360-degree video support.Add H.265 support, Multi-Camera Editor, 'Motion tracking' (Match moving). 2015.05.08 : Corel VideoStudio Pro X8 (v18): Several improvements.2014.03.05 : Corel VideoStudio Pro X7 (v17): Software become 64bits coded.
VideoStudio supports VFX-type plug-ins from providers like NewBlue. Proxy files are smaller versions of the video source that stand in for the full-resolution source during editing to improve performance. VideoStudio supports editing of high-definition video. This feature also makes final rendering much faster. A feature that Corel calls "SmartRender" renders only the edited portions of video, so a user can preview edited footage without VideoStudio creating temporary files. The soundtrack can be split from the video track, allowing the audio to play at a different pace than the video. It provides tools that let the user trim, crop, and split video tracks. VideoStudio can change apparent video playback speed, reverse it, and modify hue and saturation. The user must remove a particular color from the overlay video so that the required background or picture can appear in the foreground. However, the number of overlays allowed is limited. Users can overlay a Flash animation, an image, or text on the video. Album a slideshow effect similar to that of a photo album.3D provides assorted 3D transition effects.
FX contains assorted video effects such as 'Burn' and 'Fade to black'.VideoStudio provides several categories of video transitions, including: VideoStudio also supports direct DV and HDV capturing to disk. Different formats are supported for source clips, and the resulting video can be exported to DVD, AVCHD, HD-DVD and AVI. The software allows both storyboard and timeline-oriented editing.