UnsupportedOperationException opening Rule Configuration

[regrog]

Opening

• Windows -> Preferences -> PMD -> Rule Configuration

I get the error below.

plugin version is a snapshot
https://dl.bintray.com/pmd/pmd-eclipse-plugin/snapshots/updates/

versions:

Gradle 4.10.2
PMD 6.7.0
java 1.8
buildship 2.2.1

java.lang.UnsupportedOperationException
at java.util.Collections$UnmodifiableMap.remove(Collections.java:1460)
at net.sourceforge.pmd.eclipse.ui.preferences.panelmanagers.Configuration.filteredPropertiesOf(Configuration.java:29)
at net.sourceforge.pmd.eclipse.ui.preferences.br.RuleUIUtil.indexedPropertyStringFrom(RuleUIUtil.java:160)
at net.sourceforge.pmd.eclipse.ui.preferences.br.ImageColumnDescriptor$1.valueFor(ImageColumnDescriptor.java:28)
at net.sourceforge.pmd.eclipse.util.AbstractCellPainterBuilder.valueFor(AbstractCellPainterBuilder.java:97)
at net.sourceforge.pmd.eclipse.util.StyledTextBuilder.adjust(StyledTextBuilder.java:35)
at net.sourceforge.pmd.eclipse.util.StyledTextBuilder.access$0(StyledTextBuilder.java:33)
at net.sourceforge.pmd.eclipse.util.StyledTextBuilder$1.handleEvent(StyledTextBuilder.java:66)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5348)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1348)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1374)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1357)
at org.eclipse.swt.widgets.Tree.rendererRender(Tree.java:3152)
at org.eclipse.swt.widgets.Tree.rendererRenderProc(Tree.java:2913)
at org.eclipse.swt.widgets.Display.rendererRenderProc(Display.java:1472)
at org.eclipse.swt.internal.gtk.OS._gtk_main_do_event(Native Method)
at org.eclipse.swt.internal.gtk.OS.gtk_main_do_event(OS.java:9282)
at org.eclipse.swt.widgets.Display.eventProc(Display.java:1328)
at org.eclipse.swt.internal.gtk.OS._g_main_context_iteration(Native Method)
at org.eclipse.swt.internal.gtk.OS.g_main_context_iteration(OS.java:2116)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4181)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:818)
at org.eclipse.jface.window.Window.open(Window.java:794)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:211)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:63)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:473)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:565)
at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:397)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:5348)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1348)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4602)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4183)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1150)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1039)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:680)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:594)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:151)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
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:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
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.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:1499)
at org.eclipse.equinox.launcher.Main.main(Main.java:1472)