VMS Help CC, Messages, BLOCKEXTVLA  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> the block scope identifier "<name>" cannot
                be declared with a variably modified type because it
                has extern storage class.

 Description    Only ordinary identifiers with block scope and
                without storage class extern, or ordinary identifiers
                with function prototype scope can be declared with a
                variably modified type.

 User Action    Correct the declaration.