Yes I thought that a new add will erase all was yet existing!
Seems if a file index.htm is yet existing , its name was increasing like index-1.html so a big mess 
So what i must make for import a new Project from my computer ?
Erase first one by one each file on the project folder ? Seems multiple selection is not possible…
I don’t see a Close function on the Web Editor…I surely miss another “hiden” little thing!
Sorry for these trivial questions but that is no simple like File / New, Save, Load, Import, Export, Close
And Daniel Shiffman has not detailed that on the Web Editor videos !