Hello there, Thank you very much for reaching out to us. I'm sorry to hear that you are seeing this error code when playing with your brother. This error code is generally associated with network issues. To rule out any connection issues, we encourage you to try out our [url=https://help.bungie.net/hc/en-us/articles/360049496531-Network-Troubleshooting-Guide]Basic Network Troubleshooting Guide[/url]. If that doesn't help, we'd encourage you to review the [url=https://help.bungie.net/hc/en-us/articles/360048717852-Error-Code-WEASEL]Help Article[/url] for this particular error code, as there's some more troubleshooting that can be tried. Lastly, if none of that helps, we'd direct you to our [url=https://help.bungie.net/hc/en-us/articles/360049496751-Advanced-Troubleshooting-UPnP-Port-Forwarding-and-NAT-Types]Advanced Network Troubleshooting Guide[/url], to rule out any port/NAT issues that may be causing this to occur.