For me the error is "Cannot read property 'c2obj' of undefined".
Looking at your event, when you create the joint you set "Object2 UID" to 2.
The wire does have a uid of 2 but it doesn't have the chipmunk behavior. You can only create joints between objects with the chipmunk behavior.
In my example I used -1 for "object2 uid". That means just connect to a fixed location on the layout. The wire in my example didn't have the physics behavior either, it was just for a visual.