After upgrading Symantec Endpoint Protection (SEP) client to version 14 with Application Control (AC) component installed, you are no longer able to launch your web-based (Microsoft ClickOnce) application.
Microsoft's ClickOnce (dfsvc.exe) process causes an infinite loop in the Windows loader thread when Application Control (sysfer.dll) is injected into kernel32.
This issue is fixed in the Symantec Endpoint Protection client 14.2 RU1. For information on how to obtain the latest build of Symantec Endpoint Protection, see
Download the latest version of Symantec Endpoint Protection.