Click the output folder hyperlink to go to the folder with the HTML web page and its related files.

It might not be possible to export some of the features into HTML5. If there were any problems during export, a special list is displayed. In the list for every object you can see its type, what happened to the object during export (Skipped, Modified, etc), and some details about the problem. Most of the problems could be fixed by enabling video objects export in the Advanced tab of the HTML5 Export Parameters dialog before saving the project as HTML5. But video objects might not work properly in mobile browsers. So the ideal solution is to remove or modify the objects with problems from the list.

Click 'Open Preview' button to start a built-in web server with the new HTML5 web page. The built-in web server's port number is specified in 'Port Number'. Default is 150.
You might need to confirm the Firewall exception for this feature to work properly.