Version 12.1.6 (12.1 RU6 MP5) build 7004 (12.1.7004.6500)
For some reason, this didn't install well on Surface Pro Windows 10 Pro.
Error messages:
"symantec endpoint protection cannot open because some symantec services are stopped. restart the symantec services and then open the symantec endpoint protection"
"Symantec Endpoint Protection has detected that there are pending system changes that require a reboot. Please reboot the system and rerun the installation."
etc.
Solution:
It appears that one latest update of Windows is disrupting SEP. Go to Windows Updates and uninstall: KB4056892 (or KB4056891 or KB4056890)
uninstalling windows update: 2018-01 Cumulative Update for Windows 10 Version 1709 for x64-based Systems (KB4056892) would fix the problem - mohamed farouk