After installing Windows Updates that include KB3188730, ccSvcHst.exe crashes on startup. Symantec Endpoint Protection (SEP) client does not function properly. Reverting the security patch does not resolve the issue.
2/15/2017 4:03:44 PM Application Error Application Error va33pwpvqd001 1000 "Faulting application name: ccSvcHst.exe, version: 12.12.1.15, time stamp: 0x573cfe4d
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: 0x00000c96
Faulting process id: 0xcdc
Faulting application start time: 0x01d287cef3fd85d4
Faulting application path: C:\Program Files (x86)\Symantec\Symantec Endpoint Protection\12.1.7004.6500.105\Bin\ccSvcHst.exe
Faulting module path: unknown
Report Id: 3c225e29-f3c2-11e6-b828-0894ef02fc30"
Microsoft MS16-120: Description of the security update for the .NET Framework 3.5.1 for Windows 7 and Windows Server 2008 R2 Service Pack 1: October 11, 2016
https://support.microsoft.com/en-us/help/3188730/ms16-120-description-of-the-security-update-for-the-.net-framework-3.5.1-for-windows-7-and-windows-server-2008-r2-service-pack-1-october-11,-2016
This issue is resolved in SEP 14 MP2.