Leaflet API Change
Looks like Leaflet changed the API for adding Openstreetmap to your map in Javascript. I had to make the following changes today:
From:
L.tileLayer('https://{s}.tiles.mapbox.com/v3/{id}/{z}/{x}/{y}.png', {
maxZoom: 18,
attribution: 'Map data © +
<a href="http://openstreetmap.org">OpenStreetMap</a> contributors, ' +
'<a href="http://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>, ' +
'Imagery © <a href="http://mapbox.com">Mapbox</a>',
id: 'examples.map-i875mjb7'
}).addTo(map);
To:
L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
attribution: '© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map);