Hotfix for r227.
Still the same problem as r226, I can't preview! I use Photon, and Firebase SDK as third-party plugins (and they worked fine in r225 and before).
F12 Console shows "Uncaught TypeError: Cannot read property 'Photon' of undefined".
And no, I don't need to file a Bug report, because I can always go back to r225. If you really want r227+ features to work with Third-party plugins (i.e. for almost half of your customers) then this feedback should be taken as seriously as a "bug report". In fact, for future, you can add a "Report Problems with this release" (another comment section) on every new release page. Would make things more organised and quick. Let the bug report be for stable releases only.
It sounds like a problem with the addon. The addon developer will need to address it. We posted a compatibility update for addon developers.
Black screen with Photon addon too... :-/
Uncaught TypeError: Cannot use 'in' operator to search for 'Object' in undefined at Object.$jscomp.polyfill
It seems that this is related to the fact that the "in" operator is used on text and not on an object.