problem: the "lesson" pages do not load with EDUMA theme

I create a website on which I sell training.
The trainings are done with videos. I put these videos on google drive and I export them on wordpress.
Here is my problem: all the pages load very well but the pages of the “lessons” where the videos are present do not load.
There is no error message but just the page that does not load.

My site :

Have you tried to contact the author?

Where I can have this contact?

Here you go :smiley:

i have same problem when i upload courses and check preview it shows page not found