With so many quirky “beard” error codes in Sea of Thieves, it is easy to get them all confused with each other and tell the difference between them. A rare one is the Marblebeard error, which does not even show up on the official support site’s page on beard errors. As a result, community members have had to put together information to try to figure out what Marblebeard in Sea of Thieves means and how to solve it.
The Marblebeard error occurs when attempting to connect to the game’s servers or rejoin a game session. While this is likely due to stress on the Sea of Thieves servers, it is very possible that the error has to do with your own connection. First, it’s worth checking online whether or not the Sea of Thieves servers are functioning overall — easy sources include the official Sea of Thieves Twitter account and the Xbox Live status page.
If it isn’t a systemwide error, then it’s time to do some basic troubleshooting for your connection. A common problem leading to the Marblebeard error is your NAT type. If you are on Xbox, you can check your NAT type by hitting the home button, going to Profile & system, and selecting Settings. Under Network settings, look under Current network status to see your NAT type. Ideally, this should be listed as Open. Should you still be running into issues, then steps afterward include restarting your Xbox or whichever launcher you are using on PC, or restarting and troubleshooting your router.