Hi Team, I am creating an n-gram analysis on a text mining data however receving the error as:- Error in .jcall("RWekaInterfaces", "[S", "tokenize", .jcast(tokenizer, : java.lang.NullPointerException I have used the function: Ngramtok= function(x)NGramTokenizer(x, Weka_control(min=1, max=5)) and then using this as below:- ngram1= DocumentTermMatrix(cnt_reason,control = list(tokenize= Ngramtok)). Checked stack overflow for the error here - http://stackoverflow.com/questions/38605088/creating-ngrams-in-r where it was advised to remove the blank rows but it did not help. I have strangely used this earlier but it now not working now. Please suggest. [[alternative HTML version deleted]]