It has been observed that sometimes following error message might be displayed when stopping ScanEngine service using command "net stop symcscan"

In addition, following error can be found in application log:

Faulting application symcscan.exe, version 5.2.8.58, time stamp 0x4c08c088,
faulting module ntdll.dll, version 6.0.6002.18005, time stamp 0x49e03824,
exception code 0xc0000005, fault offset 0x00038e7c, process id 0x5a4,
application start time 0x01cc34660b87fd91.
 

This error appears to be OS-related problem sometimes pointing to driver issues, can also be generated when closing/stopping the application that is busy processing data. It is also advisable to run full system scan by filesystem antivirus to exclude any virus/malware infections.