The query building and interactive debugging tools in Studio each work in conjunction with the RDS (remote development services) feature, whether you're working with databases or templates that are stored locally or against a remote server. You can easily add a new RDS server to either of the lists of servers offered in these two tools, but you cannot edit them.
If a mistake is causing your selection of one of these listed servers to fail, you may need to edit it. You can do so using the Remote Files tab, which is the second tab on the resource toolbar at the lower left of Studio's screen (by default).