Unable to see any slide content when publishing or previewing HTML5 in firefox or chrome

I created a blank project (not a responsive one) and when I publish to html5 the output only shows the project background (from the masterslide) after the first slide (that is just an image with a button to go to the next page - no background). This happens with firefox and chrome. The flash version works fine - all objects are shown and audio work ok. I've removed the playback bar and borders in the skin editor (I've also tried with the playback bar enabled - no difference). Interestingly in safari the course displays ok though audio doesn't work (another problem i need to fix somehow).

What could be the issue and how can I fix it? I'm using Captivate 8.0.0.145 (and I can not update to the new patch) on Windows 7