guyrotty replied
Please close my question. The problem should be somewhere in my Wordpress environment.
I have two localhosts wordpress environments. Say some experimental and another one pre-production. Citylight demo install works on the experimental localhost but Elegance doesn't.
I decided to import the Elegance News to my localhost pre-production site and it worked without any problem.
So, the problem of not being able to install the wanted demo is still a question, but one for me.
Thanks nevertheless for your effort and time. Have a nice day.
Regards, Guy