EDIT

When pressing return on the end of the synonymy list a new empty record appears. When trying to save it is labeled "Click to add name" and a warning is given that an attempt was made to save a taxon/synonym with an empty name.

When trying to delete this name an NPE is thrown:

login : admin
editor version : 4.6.0.201702161652
server : test.e-taxonomy.eu (edit-test) / rem_conf_am
schema version : 4.1.0.0.201607300000
os : Windows Server 2012 R2 6.3 amd64
java : 1.8.0_121
org.eclipse.core.commands.ExecutionException: While executing the operation, an exception occurred
    at org.eclipse.core.commands.operations.DefaultOperationHistory.execute(DefaultOperationHistory.java:521)
    at eu.etaxonomy.taxeditor.model.AbstractUtility$1.run(AbstractUtility.java:345)
    at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:464)
    at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:372)
    at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:759)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:756)
    at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2649)
    at org.eclipse.ui.internal.progress.ProgressManager$RunnableWithStatus.run(ProgressManager.java:1346)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.ui.internal.progress.ProgressManager$7.run(ProgressManager.java:1184)
    at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:180)
    at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:150)
    at org.eclipse.swt.widgets.Display.syncExec(Display.java:4683)
    at org.eclipse.ui.internal.progress.ProgressManager.runInUI(ProgressManager.java:1182)
    at eu.etaxonomy.taxeditor.model.AbstractUtility.runInUI(AbstractUtility.java:657)
    at eu.etaxonomy.taxeditor.model.AbstractUtility.executeOperation(AbstractUtility.java:363)
    at eu.etaxonomy.taxeditor.editor.name.handler.DeleteTaxonBaseHandler.doExecute(DeleteTaxonBaseHandler.java:91)
    at eu.etaxonomy.taxeditor.editor.name.handler.DeleteTaxonBaseHandler.execute(DeleteTaxonBaseHandler.java:56)
    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.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
    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: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:622)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
Caused by: java.lang.NullPointerException
    at eu.etaxonomy.taxeditor.editor.name.operation.DeleteSynonymOperation.execute(DeleteSynonymOperation.java:75)
    at org.eclipse.core.commands.operations.DefaultOperationHistory.execute(DefaultOperationHistory.java:513)
    ... 52 more

This happens for both "delete" and "delete all names".

It is difficult to get rid of this empty name (only by filling it and then delete it, but also then, if the name was not yet saved an NPE is thrown when trying to delete)