You have attempted to open a database that was created with a language that is not installed on your computer. You should determine what language was specified for this database when it was created and then make sure that language is installed on your system. If the database was created with DAO, the language was specified with the locale argument of the CreateDatabase method. If the database was created with Microsoft« Access, the language was specified with the option "New Database Sort Order" on the General tab of the Options dialog box, which is available by clicking Options on the Tools menu.
Languages can be added to your system through the Regional settings of the Control Panel.