Fatal error: session_start(): Failed to initialize storage module: user (path: /tmp) in /home/serial/public_html/blabla.com/wp-inst/wp-content/mu-plugins/wp-hashcash.php on line 29
I just tried to change one user's pass from the control panel and that error popped up. some users have started to recieve the same error when they access their blogs at user.blabla.com
When I try to refresh the concrete page which gets the error everything goes back to normal after a few attempts.