Okay I found a trick to fix it :
1 - I renamed my project folder
2 - I created a new unreal project from blanc blueprint, set up all plugins like the old one, added all my C++ classes
3 - I copied/pasted all my c++ and build files from the old to the new project, compiled for UE editor development, then all my blueprints and configs files
4 - All my project is back and I can compile it !
I don’t know where was the error but the main goal is achieved 
Have a nice day !