French translation must be updated but I cannot upload new version

Hi !
I'm French user of FlashFXP 5. The software works very well but some strings in French need to be retranslated (literal translation for example).

I tried to "export" it from translation editor, but it said me "Forbidden" (I can save the translation file on my disk finally but not send the translation to FlashFXP server)

Can you fix it ?