If you're having a little trouble with Xbox Live this evening, then you're not alone. According to the Xbox Live status page, it began experiencing problems a short time ago with a couple of different services.
The two main services affected are Purchase and Content Usage, as well as Social and Gaming. Both are listed as limited, with messages stating that the Xbox team is aware of the problem and working on fixing things up.
We'll keep an eye on the service page and update this post when things are in the clear. In the meantime, if you're having issues purchasing content from the Xbox store or interacting with your friends on your Xbox One or 360, sit tight and hopefully Microsoft will have this cleared up sooner rather than later.
Source: Xbox Live Status