Thank you for your help
The folder autostart did not exist.
I have create it an have follow your instruction.
Without success. Always on English

Any ideas?

Hi guys!

When I launch Opera after booting, the default language (French) is run.
However, when I launch Opera automatically at booting (startup application), the language is English.
In my setting, my preferred languages is French and I remove all other languages.
If I restart Opera, the correct langague is French.

opera.desktop is setting : Exec=opera --lang=fr %U

Any ideas?
Thank a lot