Because resolving this problem was too long and complicated, I prefer uninstall and reinstall Ionic project.
After that get this error : Bad project type: undefined
and this too : Could not determine project type (project config: ./ionic.config.json)
I tried everything on Ionic, GitHub or stack overflow .
For each command line I get this error.
Currently I have no more ionic project. Only Ionic CLI, Cordova and node
Before I tried to create a new ionic.config.json file.
Could you please help me to resolve this problem ?