Still no solution yet. I have however found that if I comment line 9 in Zlib.pm "use Scalar::Util qw(dualvar);", the problem disappears and I am able to use the "pp" utility including both the Bleach and Squish filters.

I have re-installed Scalar-List-Utils-1.18 with success, but the problem does not get resolved...

Regards,
Niel