Roy Johnson has shown you the correct way to produce the alias. It's not really a symbolic reference, but a typeglob assignment. That is admittedly a thin distinction.

I'll show in more detail how you would use this:

#!/usr/bin/perl
use warnings;
use strict;

use vars qw/%MEClassProps/;

use Old::Code qw/markFail/; # import the old function

# . . .

# time to use it, mostly your code
sub assign_ME_problem{
    my($ontCategory, $ontNumbering, $mapwd) =@_;
    local(%problemClassProps) = \%MEClassProps;
    markFail($mapwd, $ontCategory, $ontNumbering);
    1;
}
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You were on the right track, but just missed the use of a reference to alias the typeglob.