Dear all, I have trained a J48 classifier in RWeka but when I try to predict on new data I get the following exceptions: fit <- J48(...) yNew <- predict(fit, x, type="probability"); Error in .jcall("RWekaInterfaces", "[D", "distributionForInstances", .jcast(classifier, : java.lang.NullPointerException What could be the cause of this ? I am using R version 2.10.0 on a Linux server. Thanks, Markus [[alternative HTML version deleted]]