Internal Error #993

  (#96477) An example of this error occurred during an attempt to
  macro compile a local in a block expression (INDEX..ON).  First the
  "Error BASE/1065 Argument error: &" occurred.  Then three copies of
  this error message (#993) were output.  The message "Aborted during
  termination" also accompanied this error message before the application
  came to a screeching halt in the land of the C prompt.

  () My experiences with this message occur in a custom error handler.       ~
  After receiving an error message during a stabilize of a tbrowse, the
  internal error 993 is generated as I display an array containing
  callstack information.  I'm not sure what the correlation might be --
  except for the fact that both occured within an error handler.