EDIT

first implementation added.

When trying to open Preferences-Taxonomic-NomenclaturalCode I got an NPE:

login : admin
editor version : 4.3.0.201609141050
server : test.e-taxonomy.eu / edit-test
schema version : 4.0.0.0.201604200000
os : Windows Server 2012 6.2 amd64
java : 1.7.0_65
java.lang.NullPointerException
    at eu.etaxonomy.taxeditor.preference.PreferencesUtil.setPreferredNomenclaturalCode(PreferencesUtil.java:119)
    at eu.etaxonomy.taxeditor.preference.NomenclaturalCodePreferences.init(NomenclaturalCodePreferences.java:86)
    at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceNode.createPage(WorkbenchPreferenceNode.java:57)
    at org.eclipse.jface.preference.PreferenceDialog.createPage(PreferenceDialog.java:1339)
    at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.createPage(FilteredPreferenceDialog.java:376)
    at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1230)
    at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:674)
    at org.eclipse.jface.preference.PreferenceDialog$10.run(PreferenceDialog.java:708)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.jface.preference.PreferenceDialog$9.selectionChanged(PreferenceDialog.java:704)
    at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:888)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
    at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
    at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:886)
    at org.eclipse.jface.viewers.StructuredViewer.handlePostSelect(StructuredViewer.java:1226)
    at org.eclipse.jface.viewers.StructuredViewer$5.widgetSelected(StructuredViewer.java:1251)
    at org.eclipse.jface.util.OpenStrategy.firePostSelectionEvent(OpenStrategy.java:262)
    at org.eclipse.jface.util.OpenStrategy.access$5(OpenStrategy.java:256)
    at org.eclipse.jface.util.OpenStrategy$3.run(OpenStrategy.java:433)
    at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
    at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
    at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4140)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3757)
    at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
    at org.eclipse.jface.window.Window.open(Window.java:801)
    at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.open(WorkbenchPreferenceDialog.java:215)
    at org.eclipse.ui.internal.handlers.ShowPreferencePageHandler.execute(ShowPreferencePageHandler.java:54)
    at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:293)
    at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
    at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
    at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
    at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
    at org.eclipse.ui.menus.CommandContributionItem.handleWidgetSelection(CommandContributionItem.java:829)
    at org.eclipse.ui.menus.CommandContributionItem.access$19(CommandContributionItem.java:815)
    at org.eclipse.ui.menus.CommandContributionItem$5.handleEvent(CommandContributionItem.java:805)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
    at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at eu.etaxonomy.taxeditor.Application.start(Application.java:24)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1410)

In Revision 4625a011 a check for the existence of the preference in DB is added.

Katja Luther wrote:

In Revision 4625a011 a check for the existence of the preference in DB is added.

This does not seem to fix the problem. I checked with the latest nightly (Sep. 30th)

Please also add the remark on the UI as mentioned in #note-8 before closing the ticket fully.

I think we can close this ticket now. Open issues will be checked in #5971 and are more related to writing then reading