API Playground doesn't load anymore on Firefox

It used to load on Firefox, it doesn't load anymore. (we only see the header with the Nuxeo log)

Firefox console shows:

Error: http://nuxeo.github.io/api-playground/packages/web_components/platform.js is being assigned a //# sourceMappingURL, but already has one
Error: http://nuxeo.github.io/api-playground/packages/polymer/src/js/polymer/polymer.js is being assigned a //# sourceMappingURL, but already has one
TypeError: mutating the [[Prototype]] of an object will cause your code to run very slowly; instead create the object with the correct initial [[Prototype]] value using Object.create platform.js:16
SyntaxError: Using //@ to indicate sourceMappingURL pragmas is deprecated. Use //# instead jquery-2.0.3.min.js:1
Error: http://nuxeo.github.io/api-playground/packages/nuxeo_api_playground/javascript/jquery-2.0.3.min.js is being assigned a //# sourceMappingURL, but already has one
Error: