On screen: 0x87DD0019
This one genuinely goes both ways, so the first job is telling which you are looking at.
Microsoft's explanation: this may mean that there's an Xbox Live service outage, or that you're experiencing a connection error. Two causes, opposite responses.
It occurs both when signing in on the console and in the Xbox app on Windows, and Microsoft publishes different paths for each.
There is an important exception in their article: if the code appeared during a system update or while setting up the console, Microsoft directs you to their system-update troubleshooting instead of these steps.
Check the live status above. An alert means wait. If status is clear, the path depends on where you are: the console network troubleshooter on Xbox, or Windows Wi-Fi troubleshooting on PC. And if this started during a system update, neither applies — use the update path.
Operator documentation: support.xbox.com. A note on sourcing. Microsoft's support site is a single-page application: any invented URL of the form error-code-anything returns HTTP 200 with an empty shell. So a link that looks like it works may lead nowhere, and the 0x prefix is genuinely inconsistent between articles. The URL above is the one that actually resolves for this code. This one requires the 0x prefix in the URL.
Microsoft's explanation: this may mean that there's an Xbox Live service outage, or that you're experiencing a connection error. Two causes, opposite responses.
This one genuinely goes both ways, so the first job is telling which you are looking at.
Start with: Check the Xbox status page. Microsoft's first step, and they let you subscribe to a notification for when a service recovers.