My quiz question and answers wont appear. I can see the radio buttons but even the submit button is blank. Is it because I changed the PowerPoint theme?

I don't think the theme change would do this, but maybe it can. I would try deleting and recreating a question to see if that resolves it. If it does, you may have to recreate all your questions.

Well, that would eliminate the theme issue for me. You may want to reach out to Support and see if they can look at the presentation and give you any information about why it isn't working. They can be reached at 800-945-9120