Starting April 20, 2015, YouTube shut down API version 2 and switched entirely to new YouTube API 3. Our YouTube video import WordPress plugin used YouTube’s API 2 in versions 1.1.x but switched to YouTube API 3 starting versions 1.2.x that was released on April 9th, 2015.
Users using plugin version 1.1.x will most likely see this YouTube device support video when trying to import anything using the plugin. If this is your case, we strongly suggest that you update the plugin as soon as possible by going to your Envato market account downloads page and downloading the latest available version from CodeCanyon.
The official YouTube deprecation notice can be read here.