Hi.
Did you actually uploaded te Filesystem image? I think you probably forgot to upload the files in the data folder to the board. Please, double-check that.
If you open the JavaScript console on the web browser, do you get any errors?
Regards,
Sara

I understand that it looks like there is no webpage to be displayed, which would be the case if I did not upload the page data. Html, css, favicon, and javascript  are in the data folder, main.cpp is in the src folder – have I got the folder levels incorrect – see image  https://imgur.com/a/MDyCFCY
The java console shows”crbug /1173575, non-35 module files deprecated (index 6733)”
 

II did not realize that I had to upload twice. All is good now. 
 I got lost with the instruction ” Click the PIO icon at the left sidebar”  I clicked on  .pio  and when I did not find the other items in the instruction I assumed that  I had done the necessary upload.  I admit that I was puzzled about the word icon  but hovering over the icon shows PlatformIO  not PIO, so I chose to go with .pio and then made bad assumptions because I got a report of “success”. 
Thank you for your help. I am learning a lot from the course.

I’m sorry for the misunderstanding. I’ll try to make the instructions more clear in the next eBook update.
I’m glad you’re enjoying the eBook.
I’ll mark this issue as resolved. If you need further help, you just need to open a new question in our forum.
Regards,
Sara