Unable to log into Plesk after automatic update

Hi,

Plesk ran its usual automatic update this morning but I received the following error message by email:

/etc/cron.daily/drweb-update:
ERROR: Dr.Web Updater: can not send HUP signal to Dr.Web daemon (pid=9139, error=No such process) !
See Dr.Web Updater log file for details.
run-parts: /etc/cron.daily/drweb-update exited with return code 60

Now when I try to access PLesk login page, I get the following error message:

Warning: Unknown: failed to open stream: No such file or...

Unable to log into Plesk after automatic update