When I try to execute any controller of my CodeIgniter project i receive this error:
Fatal error: Class CI_Session_files_driver contains 1 abstract method an
Problem solved by restarting Apache.
I attach the url which saved me: http://forum.codeigniter.com/thread-64763.html
In my case i did the following
Restart apache
That's it!
The files in system should not be modified. My files were modified somehow and were throwing error. I resolved my problem as below.
This should fix your problem.