STEPS TO REPRODUCE:
1. Create new HTML file and open it in VPE.
2. Enter the following line in the file:
<button style='FONT-FAMILY: "serif"'>bla bla</button>
3. Delete quote symbol (') after "serif".

RESULT:
java.lang.NullPointerException is thrown:

java.lang.NullPointerException
at org.jboss.tools.vpe.editor.toolbar.format.FontNameFormatController.setToolbarItemEnabled(FontNameFormatController.java:92)
at org.jboss.tools.vpe.editor.toolbar.format.FormatControllerManager.selectionChanged(FormatControllerManager.java:153)
at org.jboss.tools.vpe.editor.toolbar.format.FormatControllerManager.selectionChanged(FormatControllerManager.java:106)
at org.jboss.tools.vpe.editor.VpeController.selectionChanged(VpeController.java:2661)
at org.eclipse.wst.sse.ui.StructuredTextEditor$5.run(StructuredTextEditor.java:627)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.fireSelectionChanged(StructuredTextEditor.java:625)
at org.eclipse.wst.sse.ui.StructuredTextEditor$StructuredSelectionProvider.handleSelectionChanged(StructuredTextEditor.java:717)
at org.eclipse.wst.sse.ui.StructuredTextEditor$3.selectionChanged(StructuredTextEditor.java:593)
at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:162)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:160)
at org.eclipse.jface.text.TextViewer.fireSelectionChanged(TextViewer.java:2714)
at org.eclipse.jface.text.TextViewer.selectionChanged(TextViewer.java:2693)
at org.eclipse.jface.text.TextViewer$4.widgetSelected(TextViewer.java:1818)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:228)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1027)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1012)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:770)
at org.eclipse.swt.custom.StyledText.sendSelectionEvent(StyledText.java:7486)
at org.eclipse.swt.custom.StyledText.clearSelection(StyledText.java:1706)
at org.eclipse.swt.custom.StyledText.setSelection(StyledText.java:8834)
at org.eclipse.swt.custom.StyledText.updateSelection(StyledText.java:9472)
at org.eclipse.swt.custom.StyledText.handleTextChanged(StyledText.java:6095)
at org.eclipse.swt.custom.StyledText$6.textChanged(StyledText.java:5522)
at org.eclipse.jface.text.DefaultDocumentAdapter.fireTextChanged(DefaultDocumentAdapter.java:347)
at org.eclipse.jface.text.DefaultDocumentAdapter.documentChanged(DefaultDocumentAdapter.java:291)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument._fireDocumentChanged(BasicStructuredDocument.java:456)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.fireStructuredDocumentEvent(BasicStructuredDocument.java:1178)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.internalReplaceText(BasicStructuredDocument.java:1960)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.replaceText(BasicStructuredDocument.java:2415)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.replaceText(BasicStructuredDocument.java:2400)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.access$2(JobSafeStructuredDocument.java:1)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument$3.run(JobSafeStructuredDocument.java:137)
at org.eclipse.wst.sse.ui.EditorExecutionContext.execute(EditorExecutionContext.java:147)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.replaceText(JobSafeStructuredDocument.java:144)
at org.eclipse.wst.sse.core.internal.text.BasicStructuredDocument.replace(BasicStructuredDocument.java:2360)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.access$0(JobSafeStructuredDocument.java:1)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument$1.run(JobSafeStructuredDocument.java:88)
at org.eclipse.wst.sse.ui.EditorExecutionContext.execute(EditorExecutionContext.java:147)
at org.eclipse.wst.sse.core.internal.text.JobSafeStructuredDocument.replace(JobSafeStructuredDocument.java:95)
at org.eclipse.jface.text.DefaultDocumentAdapter.replaceTextRange(DefaultDocumentAdapter.java:248)
at org.eclipse.swt.custom.StyledText.modifyContent(StyledText.java:6637)
at org.eclipse.swt.custom.StyledText.sendKeyEvent(StyledText.java:7446)
at org.eclipse.swt.custom.StyledText.doContent(StyledText.java:2442)
at org.eclipse.swt.custom.StyledText.handleKey(StyledText.java:5817)
at org.eclipse.swt.custom.StyledText.handleKeyDown(StyledText.java:5842)
at org.eclipse.swt.custom.StyledText$7.handleEvent(StyledText.java:5542)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1027)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1012)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1040)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1036)
at org.eclipse.swt.widgets.Widget.wmChar(Widget.java:1368)
at org.eclipse.swt.widgets.Control.WM_CHAR(Control.java:4053)
at org.eclipse.swt.widgets.Canvas.WM_CHAR(Canvas.java:346)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3946)
at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:342)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4619)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2411)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3501)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
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:368)
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:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)
at org.eclipse.equinox.launcher.Main.main(Main.java:1287)