Cannot set property 'title' of null about bootstrap-bower

[rangrasjay]

function x(){
L.title=d[k+"Title"],
L.content=O?O(a):d[e],
L.popupClass=d[k+"Class"],
L.placement=angular.isDefined(d[k+"Placement"])?d[k+"Placement"]:o.placement;
var b =parseInt(d[k+"PopupDelay"],10),
c=parseInt(d[k+"PopupCloseDelay"],10);
L.popupDelay=isNaN(b)?o.popupDelay:b,L.popupCloseDelay=isNaN(c)?o.popupCloseDelay:c}