"no matching references found" while searching in my library

not only this

I can’t make any search among my references

when I make a search, it’s always responding “no matching references found” , even if the author name or the year are present in my library.

I linked an example (screen print) to this message. I searched the authors Wandji, and as you can see, it is present in the list of references. Nevertheless, the software answers : “no matching references found” 

do you understand my problem?