Helmut, Pierre thanks to try to help me.
The message I have is exactly: " Problème pendant le sauvegarde du fichier!"
The size of the file is around 100K.
I have done several testing. And have found some tricks. At the begining the file format was not defined and when I have defined it nothing was changed and i also had some crashes of the program... So the settings was not saved...
Since I have set the file format for each utility tools and stop Xnview properly with the Quit option in the file menu. The settings are now saved and all functions seems to work fine and the program doesn't crash anymore. I hope that can help.
May be if file format are set during the installation this problem could be fixed.