Logistic Regression - Model Training Error (H2) NullPointerException

I have a model with a binomial outcome variable.  I built it using a decision tree, but would like to try a few other model types.  Logistic Regression is the obvious next choice, but when I run it I get:  Model training error (H2O).  Error while training the H2O model java.lang.NullPointerException. Please check your input data and the parameter setup. 

The process is relatively simple - after selecting an even sample, I have an Optimize Selection (Evolutionary) node, within which is a Validation node, and within that is the Logistic Regression node.  The input data is a mix of numeric (integer, real, numeric) and polynomial data with no missing data. There are a LOT Of attributes (253) but only 1486 records.  The Optimize Selection is intended to prune that down.  (The decision tree used 4 of those variables.) 

Any insights as to what this error means or what is going wrong?  Is there a log file somewhere I need to be looking at?