After installation the console shows these 2 lines:
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/.getRaw @ registry.js:4
Failed to load resource: the server responded with a status of 404 (Not Found) http://imagizer.imageshack.us/a/img59/2623/feedlymarkpreviousasrea.png
Icon not found
After installation the console shows these 2 lines: