17 Jun 2016 WordPress Visual Composer, EventsPlus plugin and a.poplight[href^=#] syntax err
After a bit of googling, I found this: https://wordpress.org/support/topic/since-wp-upgrade-with-event-reg-60202-apoplighthref-syntax-err
I found the offending code in wp-content/plugins/eventsplus/evrplus_public_script.js and replaced a.poplight[href^=#] with a.poplight[href*=\\#]
I did not check yet to see if EventsPlus has been updated as I was in a bit of a hurry, but everything is now working.
My guess is that jQuery got updated and it no longer recognizes the href^=# syntax.