Help! I can no longer open my project!

Hello, I am in distress!

I worked on my project in Character Animator last night. I quit and this morning I open Character Animator and it shows me an error (sorry I have the software in French).

I'm really afraid of wasting all my working hours ... Is it maybe a google drive which automatically syncs the folders?

Yet I have never had a problem so far. I beg you, somebody help me solve this.