If you need to set up an API call and configure recognition languages, make sure you use correct language codes.

You can find all language codes in the help file which is located in C:\Program Files\ABBYY FineReader Server 14.0\Help\FineReaderServerOpenApi.chm in the section Open Api Overview > Recognition Languages. 

You can also export the workflow that you are using, open it with a text editor and copy language codes from there.