     # Visually highlight of the active hint (that is, the one that will be activated if the user
     # types <Enter>).
     tabCount = ((linksMatched.length * Math.abs tabCount) + tabCount) % linksMatched.length
-    @activeHintMarker?.classList.remove "vimiumActiveHintMarker"
+    @activeHintMarker?.classList?.remove "vimiumActiveHintMarker"
     @activeHintMarker = linksMatched[tabCount]
-    @activeHintMarker?.classList.add "vimiumActiveHintMarker"
+    @activeHintMarker?.classList?.add "vimiumActiveHintMarker"
 
     linksMatched: linksMatched
     userMightOverType: @hintKeystrokeQueue.length == 0 and 0 < @linkTextKeystrokeQueue.length

  # Shows the marker, highlighting matchingCharCount characters.
  #
  showMarker: (linkMarker, matchingCharCount) ->
    return unless linkMarker.hintDescriptor.frameId == frameId
    linkMarker.style.display = ""
    for j in [0...linkMarker.childNodes.length]
      if (j < matchingCharCount)

            linkActivator clickEl

    installKeyboardBlocker = (startKeyboardBlocker) ->
      if linkMatched.isLocalMarker
        flashEl = DomUtils.addFlashRect linkMatched.hintDescriptor.rect
        HintCoordinator.onExit.push -> DomUtils.removeElement flashEl

