I am wondering if anyone has an idea why I am getting this error? It happens when I select "make blu-ray disc" -> Prepare. It renders for some time then I get this.

The Blu Ray I'm trying to make has three video files. One is a properly rendered Magix AVC/AAC MP4 file (separate WAV file for audio) but the other two are MP4 files I downloaded directly from Vimeo. Should I put these Vimeo files into Vegas first and render the audio and video separably? Can I mix different file types in DVD Architect?