OK, I think you just need to do some cleanup on your text before submitting it as an array – it isn’t clear from the logging which character is causing the crash or if the crash is necessarily from the language model because the logging doesn’t have the verbosePocketsphinx on (that’s where you would be getting the warning followed by the exception), but I would strip punctuation, special characters and line breaks from your text before handing it off to LanguageModelGenerator in any case, because the presence of those items which no utterance corresponds to can have a detrimental effect on recognition:
https://www.politepix.com/forums/topic/custom-dictionary-speech-recognition-only-kind-of-working/
It’s also important to upgrade to the current versions of OpenEars and the Rejecto demo for best results with these kinds of issues, since the latest versions of both fix important language model generation and recognition issues.
If you still have these issues after upgrading to the current versions, you can show me the full log with verbosePocketsphinx on and I’ll take a look at it and we can see what the cause of the crash is.