I am a new user to Sony Vegas and have been spending the day playing around with it. I realized some of my "built in" Sony plugins are no longer under their set tabs. For example my event fx Color Corrector is no longer under the video effects tab and my Solid Color plugin under media generators is also missing. These are just two of a few that I have noticed are missing. Is there a way to recover these lost plugins?
I am not understanding what you describing at all. But try a fresh start in case their is some corruption somewhere,
by uninstalling Vegas and deleting all its folders in Program files, restart your system and then re-install Vegas.