OK I see, that helps thanks.
First thing I would do is try that same course from SCORM Cloud to see how it performs on there. If it works fine there then that points to the problem being with the LMS rather than with the course. If it doesn't work on there then that would point to the problem being in the course.
Also, if it works fine on SCORM Cloud then you can use this as evidence that there's nothing wrong with the course itself should you need to raise an issue with the people who look after Expertus One - you can send them a link to let them run it for themselves.
You should also have a look in the console whilst the course is hanging at the loading screen. Press F12 > Console and seeing if there's any errors. Feel free to post the contents here for one of us to take a look if you want.
Hope this helps