MUSH出现错误提示？

聂小倩(xqian@tj)

C:\MUSHS\lua\show_switch.lua:1091: attempt to index field 'ENCB' (a nil value)
stack traceback:
        C:\MUSHS\lua\show_switch.lua:1091: in function 'draw_bagwindow'
        [string "Script file"]:2735: in function <[string "Script file"]:2734>