Navigation editor crashing "something is wrong"

The navigation editor has stopped working suddenly.  When I click on a site to load the tree it gives the error message " Something is wrong", and stops loading.  (See picture)

Also, when editing a page, the default Percussion Navigation Widget is crashing with the error message: Problem assembling output for item (name=“index”, id=8-101-21917) with template: percNavBar. Underlying error: Array index out of range: 0 See log for stack trace.

It has been working fine for awhile, and I suspect that somebody entered some value into the Navigation editor that is causing it to crash.  Unfortunately, I’m not able to get into the navigation editor to see what it is.

Tailing the logs/velocity.log file gives this error message: 
2016-10-04 11:26:14,876 - Exception in macro #perc_processNavigationNode at 590ee2307481aa2750658cc701763992[line 25, column 1]

We are currently running CM1 Version 5.3.0 Build 201604R04 (0).

Help soon would be appreciated, because we are unable to publish until this is resolved.

Thanks

Good Afternoon - we are sorry to hear you are experiencing this issue we have created a support ticket to address. Thank you for using the Percussion community.

For what it’s worth, we also just tried restarting CM1, (the PercusionD daemon), and the issue still persists.