Published file no longer opens

Using Captivate 7, I published a course to HTML5 and SWF. This was several months ago, and everyone reported it to be opening in a browser with no problem. Now in October, none of us are able to open it in a browser even though the file/folder structure has not been altered. I tried it myself from my computer, but neither the HTML5 or SWF versions open. When the index file is clicked a browser opens, but the page itself does not. No error message appears.

This may not be a Captivate issue, but has anyone experienced this? Any input or ideas are much appreciated!