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

 next line for source display not defined

    Facility: DEBUG, VMS Debugger

    Explanation: The debugger command TYPE or SEARCH was entered
    without specifying a line number (for example, the next line
    after the last source line printed should be used). But no next
    source line is currently defined.

    User Action: Re-enter the command explicitly specifying the
    desired line number.