KACE Product Support

Unexpected Shutdown simply means: It was not initiated by the user.
In the case of KACE it was initiated by the agent using the SYSTEM service.
The agent runs a "standard" shutdown /r, which safely ends all services and does a normal reboot.
Microsoft right now does not provide any other way to do this.
You can set a GPO to remove the message if the users don't understand the meaning of the popup.
The needed GPO is found under the Admin Templates: Display Shutdown Event Tracker

Servers want a reason for shutdown/restart input to them.  You need to find out from Kace what switches are being added to the shutdown command they issue to force the restart.  You most likely will need to request that they add a comment or reason switch to the command they issue to stop this.

Usage: shutdown [/i | /l | /s | /sg | /r | /g | /a | /p | /h | /e | /o] [/hybrid] [/soft] [/fw] [/f]
    [/m \\computer][/t xxx][/d [p|u:]xx:yy [/c "comment"]]

    No args    Display help. This is the same as typing /?.
    /?         Display help. This is the same as not typing any options.
    /i         Display the graphical user interface (GUI).
               This must be the first option.
    /l         Log off. This cannot be used with /m or /d options.
    /s         Shutdown the computer.
    /sg        Shutdown the computer. On the next boot,
               restart any registered applications.
    /r         Full shutdown and restart the computer.
    /g         Full shutdown and restart the computer. After the system is
               rebooted, restart any registered applications.
    /a         Abort a system shutdown.
               This can only be used during the time-out period.
               Combine with /fw to clear any pending boots to firmware.
    /p         Turn off the local computer with no time-out or warning.
               Can be used with /d and /f options.
    /h         Hibernate the local computer.
               Can be used with the /f option.
    /hybrid    Performs a shutdown of the computer and prepares it for fast startup.
               Must be used with /s option.
    /fw        Combine with a shutdown option to cause the next boot to go to the
               firmware user interface.
    /e         Document the reason for an unexpected shutdown of a computer.
    /o         Go to the advanced boot options menu and restart the computer.
               Must be used with /r option.
    /m \\computer Specify the target computer.
    /t xxx     Set the time-out period before shutdown to xxx seconds.
               The valid range is 0-315360000 (10 years), with a default of 30.
               If the timeout period is greater than 0, the /f parameter is
               implied.
    /c "comment" Comment on the reason for the restart or shutdown.
               Maximum of 512 characters allowed.
    /f         Force running applications to close without forewarning users.
               The /f parameter is implied when a value greater than 0 is
               specified for the /t parameter.
    /d [p|u:]xx:yy  Provide the reason for the restart or shutdown.
               p indicates that the restart or shutdown is planned.
               u indicates that the reason is user defined.
               If neither p nor u is specified the restart or shutdown is
               unplanned.
               xx is the major reason number (positive integer less than 256).
               yy is the minor reason number (positive integer less than 65536).