Settings Language don't use indicated language

Support
#1

Hi,
Platform Version 7.2.11
In my app/Help/Settings set Language to Spanish ( already defined in available locales); I restarted everything but did not change the language of the application. Stay in english.
Some workaround ?.imagen

#2

Hi,
I didn’t find any way to fix the problem.
I even ran the application from a windows in Spanish without success
Thanks.

#3

Hi,
Have you attached any Spanish translation addon to your project?

#4

Thanks for your answer.
I will follow your advice.
In which manual do I find these indications?

#5

This is the addon:

Detailed instructions are here: