Please read first this: https://www.vegascreativesoftware.info/us/forum/newbluefx-transitions-5-ultimate-missing--115419/

Which version do you have, Movie Studio 16 Platinum or Suite? In Suite they are included in the Supreme Package. Have you installed that? (https://www.vegascreativesoftware.info/us/forum/faq-where-can-i-download-vegas-pro-and-other-vegas-software--104782/ section 5 Direct Links, see the advice under Movie Studio 16 there.)