If you are experiencing the above error message, there could be one of two problems occurring. Xbox Live or Sea of Thieves could be experiencing service-related errors, these can be checked here:
Xbox Status: Check Status
Sea of Thieves Status: Check Status
Or, if you are using an Xbox, you may have an old or not updated payment option in place. If this is the case, please use another payment option, or release the current payment option and re-enter it.