id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 31141 translation.E004 shouldn't be raised on sublanguages when a base language is available. Enrique Matías Sánchez Mariusz Felisiak "According to Django documentation: ''If a base language is available but the sublanguage specified is not, Django uses the base language. For example, if a user specifies de-at (Austrian German) but Django only has de available, Django uses de.'' However, when using Django 3.0.2, if my settings.py has {{{ LANGUAGE_CODE = ""de-at"" }}} I get this error message: {{{ SystemCheckError: System check identified some issues: ERRORS: ?: (translation.E004) You have provided a value for the LANGUAGE_CODE setting that is not in the LANGUAGES setting. }}} If using {{{ LANGUAGE_CODE = ""es-ar"" }}} Django works fine (es-ar is one of the translations provided out of the box). " Bug closed Core (System checks) 3.0 Release blocker fixed pope1ni Accepted 1 0 0 0 0 0