Library /sys$common/syshlp/dbg$help.hlb DEBUG, Messages, ALRDYCONNECTED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 a debugger has already connected to the desired process.

    Facility: DEBUG, VMS Debugger

    Explanation: The process you are trying to connect to is already
    connected to a debugger (maybe your current debugger). There can
    only be one connection at a time.

    User Action: Check to see if you have already connected (SHOW
    PROCESS/ALL) to the desired process. If not, then some other
    debug session is connected to it. Disconnect the other debugger
    from the desired process before attempting to reconnect your
    session.