How to edit Team Build Types

        Now  in VSTF Team explore,When we create a  Team Build Type,we can't edit from UI. if we input the error  build type name.
        But we can edit it throught below steps

To edit Team Build Type, for example, do the following as below,
        1.       Open solution from source control database.
        2.       Open "Source Control Explorer" window 
        3.        At Source Location : $(project name)/TeamBuildTypes/(your build type name) 
        4.        Right click the file "TFSBuild.proj",Get the Latest version, then Check it out. 
        5.        Then double-click this file and edit it in the XML editor. 
        6.        After modified, save it and check it in.

        Now your change to the Build Type will be valid.

(FYI..I can edit the Team Build Type on build VSTF RTM.50727.140 following these steps.Good Luck.)