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Email templates are not translating - I created a new database and added Spanish language to the existing English. None of the "Send by Email" templates translate.
I then created a new database and added English to the existing Spanish but all the templates are still in English.
This has been like this for a week now. Seems you broke Odoo.
After doing what @Mindaugas said, confirm that the customer/vendor you are sending the email to has the desired language in its contact settings. Also if you want to fully edit the template, for then to translate you should do it manually from views and templates in the settings.
when activate language, generate missing terms. after that, you should see all translates. also, do not change source value, change translate value.
There is an actual bug in 15.3 Enterprise. Translations are not working
1. Use the live chat to ask your questions.
2. The operator answers within a few minutes.
can not post print screen.
so go to email template (settings/technical).
edit. on right corner you will see en and there go translate(checked on 15v)