The Document Lists API will cease to work on April 20 (source)
Need to migrate from that:
Here's what you need to do:
1) Determine if you have an application that makes requests to these types of URLs:
* https://docs.google.com/feeds/
* https://docs.googleusercontent.com/
* https://spreadsheets.google.com/feeds/
2) Migrate the applications to Drive API.
The Document Lists API will cease to work on April 20 (source)
Need to migrate from that: