WARNING: This message is directed to the people who works directly with the develop branch from github.
Now, the languages folder is placed in: ./oc-content/languages/ If you don't do a new install, you should move the content of ./oc-includes/translations/ to ./oc-content/languages/
P.D: I've tried as follows: adding a new language from oc-admin, using this language in the theme and oc-admin, deleting the language.