Impossible preview Cp2017

Hi, I hope that someone can help me: yesterday I've upgrade my Mac OS, now I've the new "high sierra OS". Suddently Captivate started to do like you see in this pic. If I try to publish in html5, or simpli to preview my project I cant't see that.
I only see the load icon. My project don't have big image, or video or something else that can give me problems.
TNX!
Marco
