In response to your request, you will find below four screencasts. The first one showing what I see when trying to add a picture, the second one the next step, etc. The last one is the final result showing that it’s impossible to do anything.
Please note that the same problem occurred on the "commercial" site when I updated SP PB from 3.8.8 to 4.0.1.
I then reinstalled a copy of the "commercial" site with SP PB 3,8,8 to avoid this issue.
Thanks for your help!
I hope it will work but I don't know how to add a document to this message