Nullpointer in Lib SVM Learner

Hi everyone,

I am currently getting a Nullpointer Exception after running a LIBSVMLearner Node (Weka 3.7, epsilon-SVR) repeatedly in a parameter optimization loop.
It works fine for many iterations, and then suddenly stops.

The log file reads:

DEBUG : KNIME-Worker-15 : LocalNodeExecutionJob : LIBSVMLearner : 0:110 : Caught "NullPointerException": null
    at libsvm.svm.svm_get_svm_type(
    at org.knime.ext.libsvm.port.LIBSVMPortObject.getSummary(
    at org.knime.core.node.Node.setOutPortObjects(
    at org.knime.core.node.Node.execute(
    at org.knime.core.node.workflow.NativeNodeContainer.performExecuteNode(
    at org.knime.core.node.exec.LocalNodeExecutionJob.mainExecute(
    at org.knime.core.node.workflow.NodeExecutionJob.internalRun(
    at org.knime.core.util.ThreadUtils$RunnableWithContextImpl.runWithContext(
    at org.knime.core.util.ThreadUtils$
    at java.util.concurrent.Executors$
    at org.knime.core.util.ThreadPool$
    at org.knime.core.util.ThreadPool$

Any idea what I could do?
I have tried setting the Learner Type via a Flow Variable, that didn't help.
I have also checked the optimization parameters(gamma and epsilon), they are both somewhere in the middle of their range and not zero.

KNIME Version is 3.4.0.

Kindest regards,

Hi Mol1hua,

can you provide your workflow so we can reproduce the issue?


Hi Marten,

Thank you for your reply!

I had to move the workflow to another computer, and the issue seems to have resolved itself somehow. Maybe it was a workspace hiccup?

Anyway, it seems I cannot reproduce it myself. ;-)

Kindest regards,