When Symantec Endpoint Protection 12.1 RU3 (SEP) and Websense Endpoint 7.7.1629 are installed simultaneously on a Windows 7 or Windows 8 computer, some applications fail to load with an exception code 0xc0000005. Any one of the following actions are known to prevent the issue from occurring:
1. Uninstalling SEP's Application and Device Control feature
2. Uninstalling Websense Endpoint
3. Adding ADC Exceptions for the affected application. It appears that preventing sysfer.dll injection resolves the issue.
Example of said error from Application Event Viewer log from an affected machine: