Export workflow bug?

[Aswin]

Dear Knimers,

I encountered a problem after constructing an example workflow for a different post https://forum.knime.com/t/pca-node-is-slow-compared-to-r-snippet-python-script/40601/3?u=aswin

Ubuntu 20.04, Knime 4.5.1. (Perhaps relevant: alongside I also still have Knime 4.3.4 installed)

• Start knime, no tabs open except welcome page.
• Create new workflow “KNIME_project31”.
• Insert a single “Table creator” node, create a dummy 1-column, 1-row table, executes fine
• Save, no problem.
• Click “Export KNIME workflow”… Nothing happens!

A new entry in the logfile appeared during that action:

!SESSION 2022-03-14 18:41:36.296 -----------------------------------------------
eclipse.buildId=unknown
java.version=11.0.10
java.vendor=AdoptOpenJDK
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US
Command-line arguments:  -os linux -ws gtk -arch x86_64

!ENTRY org.eclipse.ui 4 0 2022-03-14 18:45:15.374
!MESSAGE Unhandled event loop exception
!STACK 0
java.lang.NullPointerException
	at org.knime.workbench.explorer.view.actions.export.WorkflowExportWizard.addPages(WorkflowExportWizard.java:116)
	at org.eclipse.jface.wizard.WizardDialog.createContents(WizardDialog.java:632)
	at org.eclipse.jface.window.Window.create(Window.java:431)
	at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1094)
	at org.knime.workbench.explorer.view.actions.export.WorkflowExportHelper.openExportWizard(WorkflowExportHelper.java:84)
	at org.knime.workbench.explorer.view.actions.export.WorkflowExportApplicationAction.run(WorkflowExportApplicationAction.java:103)
	at org.eclipse.jface.action.Action.runWithEvent(Action.java:474)
	at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:580)
	at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:414)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5831)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1427)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:5092)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4570)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1157)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1046)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:644)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:551)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:156)
	at org.knime.product.rcp.KNIMEApplication.start(KNIMEApplication.java:183)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1461)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1434)

[Andrew_Steel]

Hi @Aswin,

I cannot reproduce this error. Are you using the same workspace for both KNIME versions? What happens if you use a different workspace? Does the error occur then as well? If not, the error could be due to a corrupted workspace, e.g. caused by a faulty save operation in your PCA workflow.

Best regards
Andrew

[Aswin]

Dear @Andrew_Steel

Yes I am using the same workspace for both versions. Export workflow stopped working for both versions. It stopped working for all workflows, not just the PCA workflow.

When I make a fresh, new, empty new workspace folder, and point both versions to this new workspace, Export workflow works again in both versions.

Emptying my custom tmp directory has no effect.

Solution: when I rename the “.metadata” folder in my workspace to something else, “export workflow” works again… But unfortunately, all my settings are lost. I guess I just have to customize everything again.

Best
Aswin

[bruno29a]

Hi @Aswin ,

There are huge differences between Knime 4.3 and 4.5, and a node in 4.3 might be a deprecated one in 4.5.

Just based on the above, I can see how it can be a problem using the same workspace for both versions. The same workflow might not work the same way in Knime 4.3 and 4.5. There is a great chance that the .metadata is corrupted because of that, and that could be confusing for Knime when it’s trying to export the workflow.

[djarrett]

I am also unable to export my workflows. Pressing the export button gives no response.