My issue is solved, I had to re-install Steam and Steam library in the same folder to fix this glitch. To resume, everyone that had this problem solved it by using one of those solutions :
1- Run the .exe with the option "Run as administrator"
2- Translate the folder names in english if you are not using latin alphabet
3- Check if everything is OK with picture names in /steam/steamapps/common/Pillars of Eternity/PillarsofEternity_Data/data/art/gui/portraits/player/(female or male)/
4- Re-install Steam library and the game in the original Steam folder on the same HDD
Thank everyone for your help and enjoy your gaming experiences
