It might happen the hardware box, such as NG500, became unresponsive for a certain period of time. The workaround with power cycling fixed the crashing problem.
Upon further investigation, the dmesg output is showing the following output:
ACPI Exception: AE_NOT_FOUND, While evaluating Sleep State [\_S4_] (20140424/hwxface-580)
Kerio Control is based on Linux kernel version 3.16. According to the Linux bug report system, the issue happens on the hibernation/suspend state. According to other forums, the issue is limited to specific chipset not being compatible with Linux kernels 4.5 and 4.6.
The workaround based on the bug report is to disable asynchronous suspend which will cause device drivers' suspend and resumed synchronously so that the system resumes normally. For more information, please refer to Sys power docs.
- Ensure to create a backup of your Kerio Control NG500.
- Access Kerio Control's Shell Using SSH.
- Run the following command:
echo 0 > /sys/power/pm_async
- Reboot Kerio Control.