Decision Tree Learner Execute failed: ("ArrayIndexOutOfBoundsException"): -1

Hello,

This is my first time working with Knime and I am just testing things out right now. When I tried to use a decision tree learner node I realized that it wasn't using all of the columns of the data set that I imported. When I try to force the root split on any of the columns that weren't used in the decision tree I get this error.

ERROR Decision Tree Learner 0:4        Execute failed: ("ArrayIndexOutOfBoundsException"): -1

I can't seem to figure out why it doesn't like those columns. All of the columns in the data set have nominal values. The columns that aren't being used have many possible values (between 20 and 100s), while the columns that the tree uses only have between 3 and 5 possible values. 

Thanks in advance for any help! 

P.S. Won't be able to provide the data set as it is customer data