I have seen plenty of previous messages related to my problem, but no answer could get rid of my "500 Server internal Error" so I try to post my conf to get help.
Several things to check for.
pip freeze | grep django
)if you are using apache 2.4 + change the following
Order deny,allow
Allow from all
to
Require all granted
Edit suggested by @marcoooo (OP) : don't put virtualenv base dir under any home dir which do not have 'x' flag, apache www-data user won't be able to activate the virtualenv either.... Many thanxs to e4c5 for his help, and saved my day (and nights)