Limitations for Youtube
Component uses Youtube Data API for some of its features. This API has daily quota. Excess of quota would result in inaccessibility of API-dependent features for all users of the component (quota resets at midnight Pacific Time (PT)).
With that said, some features that potentially may result in high quota usage are limited or disabled unless custom Youtube API key is specified.
Limited features
Auto-updated playlists
If custom Youtube API key is not set, component retrieves playlist content using RSS. This is legacy way to get playlist content, and it is limited to 15 videos. Thus update may result in a gap if playlist was not updated for a long time.
Load channel or playlist... action
This action is placed in main menu File Youtube Source.
The use of fy+search URL scheme is forbidden if custom Youtube API key is not set. Maximum number of items is limited to 1000.
Lyrics source
It is about custom source for "Lyric Show Panel 3" component.
Option Perform subtitles search for external sources is disabled if custom Youtube API key is not set.
Custom Youtube API key
You can use your own Youtube API key in the component. In this case it will not limit anything.
To enter API key, go to component preferences Maintenance Youtube API key.
To obtain API key, follow instructions in this topic (steps 1-3). In step 2 (obtaining authorization credentials) follow instructions for API key creation. When selecting API key type, select Browser key type.
Help Limitations for Youtube