drwx-wx-wt 2 root root 4096 Feb 11 20:09 /var/lib/php5/

Maybe helpful ?

I've tried to install selfoss on my web server, but couldn't manage it.

Here is what's done:
1. I uploaded selfoss directory on my server, and renamed to "reader" to have an access using my address http://hookme.fm/reader/
2. I granted root priveleges to mysql db in defaults.ini
3. I set up permissions on data folders and public to 777.
4. And received such a message:

Internal Server Error

session_start(): open(/var/lib/php/session/sess_6p2ltr8didmpoekoisrqi32rs6, O_RDWR) failed: Permission denied (13)

What should I do next?

Thanks everyone.