Hi,
Sorry for my time away, I'm back on this problem.
So, you were right, I was compiling libbson and libmongoc in Debug mode instead of Release.
That did correct the error, but I got some new ones.
I got more than 2000 error like this one : error LNK2001: unresolved external symbol __imp_mongoc_read_prefs_new
I tried with the mongo-c-driver version 1.7 and 1.6.3, but it changes nothing.
Maybe you have an idea ?
Thanks for helping :)