Finished project will not preview. Other projects preview and publish without a problem.

FYI: The link you have added to your post is a localhost link that would only work from your own computer.  It cannot be reached by other users.  This is the link that Captivate generates when you preview a project.  It's basically just a temporary web server environment to allow you to see your course content on your own PC.  For anyone else to see the project output you would need to upload the published output to a web server accessible from the general internet.

As to why your project is currently showing only a blank page I cannot say.  But the usual reason is that there is something in one of the slides that is causing the issue.  To debug this type of issue, I usually suggest taking a copy of your project so that you don't ruin your main project and use the copy to experiment. Try hiding half the slides in the project and then attempting a republish/Preview.  If the project works then, try hiding the other half of the slides instead.  You can use trial and error to try and locate where in the project the issue exists.