Some language packs available on Tesseract's github support vertical orientations of Chinese (chi_sim_vert and chi_tra_vert). Trying to specify them via TesseractOCRConfig.setLanguage(String language) results in an exception because the regex is not expecting another underscore in the name.
What is the reason behind validating language options?
Either way, I'd be more than happy to supply a patch. Thank you.