I had it configured right, but then I decided to reinstall my Debian (switching from wheezy to jessie version by the way). Here\'s the problem:
I have a python mod_w
I solved it finally. pxl was half-right, because not only Allow from all should be replaced by Require all granted, but also Order allow,deny is no longer necessary. It turns out to be the reason for my error. Complete script alias config should be like this:
WSGIScriptAlias /huh /mnt/doc/Python/www/index.py
Require all granted
And it works.