We have made the switch to Lightning, without allowing the users to switch back.  There is one intermittent, but recurring pop-up bothering our users.  When they navigate, sometimes they get a pop-up that says Sorry to Interrupt  This page has an error.  You might need to refresh it.  [NoErrorObjectAvailable] Script Error.  It occurs on pages other than just the Home page.

We haven't written or added any new lightning components, other than what the many AppExchange packages have added.  Any ideas how to stop it?  TIA!