Could be the "é" in the "Clément" on the file path (and that's a bug).
Have you updated the MCC to the latest version?
If yes and that's still happening, can you try copying that .mfprojz file to a simpler file path (like C:\tmp\) and try importing it from there?
If that works, then it's almost certain that it's a char issue if not, it might be something else more obscure to figure out.
Edit: ok, I just tried it myself, exporting a project to a folder named "C:\Clément" and got a similar error. I've reported this issue to Arturia but you may want to do the same through Support, so this bug can be fixed in the MCC