Loading Difficulties - Review 360

Hey guys,

I have a problem, which I can not solve by myself:
I always upload my e-learning courses on Review360 so that employees can give their feedback on different topics.
Today, I uploaded two courses... all went good - I can see them on Review 360. I open one of them... all good - I can see the starting layer.

I have a button on the layer to click on the next slide ... I click on it... but suddenly, the loading symbols (three points) appears and I am stuck on the fist slide with the loading symbols...

I have deleted the course a few times on Review360... uploaded it again... then changed the name of the file and uploaded it again ...
But that all didn`t work - every time when I want to go to the next page ... the loading symbols come up!

Would be nice if somebody can help me with the problem. 

Regards, 

Sebastian