Weka Scoring PDI Plugin - Error Creating Step

[fdaher]

Hello guys,

I am experimenting an error on PDI when I try to create a Weka Scoring Step on my transformation. This is weird because I was able to do it sucessfully a week ago. I am running PDI 7.1 on Ubuntu Linux 16.04 LTS, Weka Scoring Plugin version 4.x, installed from the PDI Marketplace. I also tried to run using another machine - Windows 10, same PDI 7.1 / Weka Scoring Plugin 4.x from Marketplace - and the error was the same.

The error message shows up inside a pop-up windows, as follows:

"Error creating step"
"I was unable to create a new step"

The log shows:

java.lang.LinkageError: loader constraint violation: when resolving overridden method "org.pentaho.di.scoring.WekaScoringMeta.loadXML(Lorg/w3c/dom/Node;Ljava/util/List;Ljava/util/MapV" the class loader (instance of org/pentaho/di/core/plugins/KettleURLClassLoader) of the current class, org/pentaho/di/scoring/WekaScoringMeta, and its superclass loader (instance of java/net/URLClassLoader), have different Class objects for the type org/w3c/dom/Node used in the signature
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
at java.lang.Class.getConstructor0(Class.java:3075)
at java.lang.Class.newInstance(Class.java:412)
at org.pentaho.di.core.plugins.PluginRegistry.loadClass(PluginRegistry.java:535)
at org.pentaho.di.core.plugins.PluginRegistry.loadClass(PluginRegistry.java:366)
at org.pentaho.di.trans.step.StepMeta.<init>(StepMeta.java:303)
at org.pentaho.di.trans.TransMeta.loadXML(TransMeta.java:3021)
at org.pentaho.di.ui.spoon.TransFileListener.open(TransFileListener.java:61)
at org.pentaho.di.ui.spoon.Spoon.openFile(Spoon.java:4623)
at org.pentaho.di.ui.spoon.Spoon.openFile(Spoon.java:4283)
at org.pentaho.di.ui.spoon.Spoon.openFile(Spoon.java:4220)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:313)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:157)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:141)
at org.pentaho.ui.xul.swt.tags.SwtToolbarbutton.access$100(SwtToolbarbutton.java:48)
at org.pentaho.ui.xul.swt.tags.SwtToolbarbutton$1.widgetSelected(SwtToolbarbutton.java:96)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:1366)
at org.pentaho.di.ui.spoon.Spoon.waitForDispose(Spoon.java:8022)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:9277)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:692)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.pentaho.commons.launcher.Launcher.main(Launcher.java:92)
java.lang.LinkageError: loader constraint violation: when resolving overridden method "org.pentaho.di.scoring.WekaScoringMeta.loadXML(Lorg/w3c/dom/Node;Ljava/util/List;Ljava/util/MapV" the class loader (instance of org/pentaho/di/core/plugins/KettleURLClassLoader) of the current class, org/pentaho/di/scoring/WekaScoringMeta, and its superclass loader (instance of java/net/URLClassLoader), have different Class objects for the type org/w3c/dom/Node used in the signature
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
at java.lang.Class.getConstructor0(Class.java:3075)
at java.lang.Class.newInstance(Class.java:412)
at org.pentaho.di.core.plugins.PluginRegistry.loadClass(PluginRegistry.java:535)
at org.pentaho.di.core.plugins.PluginRegistry.loadClass(PluginRegistry.java:366)
at org.pentaho.di.ui.spoon.Spoon.newStep(Spoon.java:6692)
at org.pentaho.di.ui.spoon.trans.TransGraph$5.drop(TransGraph.java:654)
at org.eclipse.swt.dnd.DNDListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.notifyListeners(Unknown Source)
at org.eclipse.swt.dnd.DropTarget.drag_data_received(Unknown Source)
at org.eclipse.swt.dnd.DropTarget.Drag_Data_Received(Unknown Source)
at org.eclipse.swt.internal.gtk.OS._gtk_drag_get_data(Native Method)
at org.eclipse.swt.internal.gtk.OS.gtk_drag_get_data(Unknown Source)
at org.eclipse.swt.dnd.DropTarget.drag_drop(Unknown Source)
at org.eclipse.swt.dnd.DropTarget.Drag_Drop(Unknown Source)
at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method)
at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(Unknown Source)
at org.eclipse.swt.widgets.Display.eventProc(Unknown Source)
at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method)
at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:1366)
at org.pentaho.di.ui.spoon.Spoon.waitForDispose(Spoon.java:8022)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:9277)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:692)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.pentaho.commons.launcher.Launcher.main(Launcher.java:92)

Could you guys please give me some light here?!

I thank you in advance.

Cheers,
Flavio.

[fdaher]

I have manage to get Weka Scoring Plugin to work again on PDI my 7.1.

After trying uninstalling PDI Plugins and Weka Packages, once at a time, I've discovered that - somehow - the conflict was with Auto-WEKA Package: soon after I uninstalled it, PDI's Weka Scoring Step worked flawlessly. Installed Auto-WEKA again, and then Weka Scoring stopped working throwing that same error.

Regards,
Flavio.

[nitinthakkar]

Hi fdaher

I was facing the same issue and I found that when you install all the packages from weka. it will store in C:\Users\username\wekafiles

so I have just renamed that folder and my weka scoring plugin works fine. Hope it will work for you also

Thank you