Please refer to https://www.vegascreativesoftware.info/us/forum/important-information-required-to-help-you--110457/ and provide more information about your computer especially in re the GPU and the media that you are using (a detailed MediaInfo report would be great). Also, what 3rd party plugins, if any, are you using? There's a huge leap between VP12 and VP19 so the crashing suggests that there's something happening on your computer that is causing a problem.