To be specific, it takes an image that is a different size from the project to trigger this bug.
It looks like there’s a problem in that if the image that TS is applied to, doesn’t match the project dimensions, TS/Vegas either flips or blacks out the image.
My project settings are 1280x720x8 and if I apply TS to the image attached at https://forum.borisfx.com/t/vegas-pro-title-studio-jpeg-black-screen/8620, it either blacks it out or flips it, depending on the fx chain.
Boris has looked at the issue and thinks that it's a Vegas problem. Hopefully by reporting it to both, they'll both be up to speed by the time someone starts looking at the issue.
There's a sample project at https://forum.borisfx.com/t/vegas-pro-title-studio-jpeg-black-screen/8620