Okay, so, after Vegas completely crashed my computer, I restored a drive image, only to find out that projects would no longer load.
Several solutions exist, such as updating drivers, disabling waveforms and previews, etc., but, I found the solution hinted at, but not confirmed. I have confirmed it!
If you have any NewBlue effects installed, and they are being used in a project that cannot load, uninstall those effects – presto! It’s fixed.