Preview Function Stalling

I am having a problem with my 'preview this slide' function in my project.  I have twice recreated the project.  At first it works but then ultimately when I try to preview to slide to make sure the triggers are working it stalls and I get a message that there is something wrong.

The strange thing is I can publish the project and everything works.  I don't want to have to publish the project every time I add a new trigger or interactive element to see if it's working.

Any suggestions?  I

've tried attaching the project to send for inspection purposes but it's too large and won't upload on this forum.