Images problem after migration
I fixed this problem going to sites/default/files/.htaccess file and commenting 

# Options None
# Options +FollowSymLinks


After that I had some other broken images but there are some wrong address in the nodes  tags linked to
/subdirectory-of-staging-server/sites/default/files
instead
/sites/default/files

Thank you for all the comment who help me to debug the error ^^