Uncaught TypeError: onItemHover is not a function

Hi There, I'm running into a console error on a vertical menu where when I do a mouseover. Note that I have a horizontal menu on the same page (with a dropdown) that's not throwing this error.

Here's the console error:
Uncaught TypeError: onItemHover is not a function
at MenuItem._this.onMouseEnter (MenuItem.js:54)
at HTMLUnknownElement.callCallback (react-dom.development.js:100)
at Object.invokeGuardedCallbackDev (react-dom.development.js:138)
at Object.invokeGuardedCallback (react-dom.development.js:187)
at Object.invokeGuardedCallbackAndCatchFirstError (react-dom.development.js:201)
at executeDispatch (react-dom.development.js:466)
at executeDispatchesInOrder (react-dom.development.js:488)
at executeDispatchesAndRelease (react-dom.development.js:586)
at executeDispatchesAndReleaseTopLevel (react-dom.development.js:597)
at Array.forEach ()
at forEachAccumulated (react-dom.development.js:565)
at runEventsInBatch (react-dom.development.js:728)
at runExtractedEventsInBatch (react-dom.development.js:737)
at handleTopLevel (react-dom.development.js:4201)
at batchedUpdates (react-dom.development.js:12537)
at batchedUpdates (react-dom.development.js:1939)
at dispatchEvent (react-dom.development.js:4282)

Here's the code:

<Menu >
<MenuItem key={props.props.groupId+'-create-event'}><Link to={props.props.rootUri + "/create-event"}>Create Event</Link></MenuItem>
</Menu>

All the props variables are valid.

Start by reproducing the vertical-menu hover error and inspect MenuItem.js at line 54, then compare the vertical and horizontal menu usage described in the report. Determine why onItemHover is not callable in the vertical case; done means hovering the vertical item no longer throws the reported TypeError while the horizontal menu still works.