/sys$common/syshlp/helplib.hlb UIL, Compile Time Errors, SRC_LIMIT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  SEVERE:  The compiler has a fixed limit for the number of source and
  include  files  that it can process.  This number is reported in the
  message.

  USER ACTION:  Use fewer include files.