Xbox Live social services including friend list, party chat and logging in are currently suffering from connectivity issues on Xbox One and Xbox 360.
At the time of writing the Xbox Live Status page does not currently reflect the problems, but we can confirm that the service is having difficulties.
The Xbox Support Twitter did acknowledge service problems as well as down detector.
Xbox Live and PSN took a hit last year when the Lizard Squad were running rampant but it seems the group is back to their old tricks once again.
@tnorris29 Our teams are working hard to resolve this current issues. Thanks for your continued patience. ^FC— Xbox Support (1-5) (@XboxSupport) April 19, 2015
Related Forum: Xbox Forum