Exception when word is missing in the dictionary

I tried the demo app, it works fine but when I tried to integrate my own .jsgf grammar file it is giving error when I tried same thing using .lm file for the same dictionary it is working fine .

I referred to PocketSphinx android demo runtime exception link but it didn't help me out

Following is the code snippet:

private void setupRecognizer(File assetsDir) throws IOException {
        // The recognizer can be configured to perform multiple searches
        // of different kind and switch between them
        File modelsDir = new File(assetsDir, "models");
        mRecognizer = defaultSetup()
                .setAcousticModel(new File(assetsDir, "en-us-ptm"))
                .setDictionary(new File(assetsDir, "cmudict-en-us.dict"))
                .setRawLogDir(assetsDir)
                .setKeywordThreshold(1e-10f)
                .setFloat("-beam", 1e-30f)
                .setBoolean("-allphone_ci", true)
                .getRecognizer();
        mRecognizer.addListener(this);
        File languageModel = new File(assetsDir, "commands_gram.gram");
        mRecognizer.addGrammarSearch(COMMANDS, languageModel);
    }

Following is the error

E/cmusphinx: ERROR: "fsg_search.c", line 141: The word 'next' is missing in the dictionary
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1

Process: java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818) 
Caused by: java.lang.RuntimeException: Decoder_setJsgfFile returned -1
at edu.cmu.pocketsphinx.PocketSphinxJNI.Decoder_setJsgfFile(Native Method)
at edu.cmu.pocketsphinx.Decoder.setJsgfFile(Decoder.java:139)
at edu.cmu.pocketsphinx.SpeechRecognizer.addGrammarSearch(SpeechRecognizer.java:234)
at com.package.ui.SphinxSpeechRecognizerActivity.setupRecognizer(SphinxSpeechRecognizerActivity.java:284)
at com.package.ui.SphinxSpeechRecognizerActivity.access$400(SphinxSpeechRecognizerActivity.java:29)
at com.package.ui.SphinxSpeechRecognizerActivity$3.doInBackground(SphinxSpeechRecognizerActivity.java:239)
at com.package.ui.SphinxSpeechRecognizerActivity$3.doInBackground(SphinxSpeechRecognizerActivity.java:233)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818) 

Also I realized that any .jsgf grammar file I am using it is not detecting the last word from the dictionary. before it was working fine after I changed to my own .jsgf grammar file it is giving exception

This line:

E/cmusphinx: ERROR: "fsg_search.c", line 141: The word 'next' is missing in the dictionary 

tells you need to add the word 'next' to the dictionary. You used this word in your JSGF grammar, but it was missing in the dictionary. Words are case-sensitive, so you need to make sure you use proper case.