PowerPoint slides not showing in Captivate 7 project

In short, I have created the same type of training video hundreds of times. But today, something is off and I can’t quite figure out what the problem is or what is wrong. I create the course in captivate and I publish to HTML and upload to an LMS.  Starting today, everything in the course is fine EXCEPT for the slides created from PowerPoint – those appear blank.  the audio plays, the course progresses normally… but the slides are white (blank) until we get to the software demonstration video. Then it shows the video playing.