The server will not restart with the watchdog module installed: the system crashes while rebooting (
shutdown -r now). The server can only be restarted via a forced shutdown.
The issue is caused by an incorrect watchdog init script,
This is a software issue. Its ID is PPPM-822. The issue was fixed in Parallels Plesk Panel 11.5.30 MU#15.
Install the latest Micro-Updates:
#/usr/local/psa/admin/sbin/autoinstaller --select-release-current --install-component base --reinstall-patch