pop-up error message

[jparish3]

Uncaught TypeError: Cannot read property 'on' of undefined at i.addTo (popup.js:94) at HTMLElement._attachedPopup (mapbox-gl-popup.js:312) at Object.runMethodEffect [as fn] (property-effects.html:904) at runEffectsForProperty (property-effects.html:168) at runEffects (property-effects.html:130) at HTMLElement._propertiesChanged (property-effects.html:1899) at HTMLElement._flushProperties (properties-changed.html:373) at HTMLElement._flushProperties (property-effects.html:1731) at HTMLElement.ready (property-effects.html:1847) at HTMLElement.ready (element-mixin.html:596)