Hello

I am conducting a study in which the use naive Bayes, and the goal is to get the model, specifically the table of conditional probabilities associated with each variable. However, in the table for each variable appears a class unknow, as the probability of that class. But my base does not contain missing vaues. What can be cause this and how correcting? Because it was not supposed to show that value, only the class values for each variable.
I hope to help me,
Greetings!