UPDATE: another reason for this error may be – https://sichent.wordpress.com/2014/11/21/icap-error-when-filtering-https-response-headers/
Current version of Diladele Web Safety (18.104.22.168CAF) may crash upon start when improperly configured. The fact that qlproxyd daemon cannot drop root privileges because there is no “qlproxy” user configured results in the exception (unhandled) which in turn results into core dump. For properly configured system impact is minimal as DEB, RPM installer makes sure such “qlproxy” user exists after installation. Fix for this bug will be included into upcoming qlproxy 3.3. See issue https://github.com/ra-at-diladele-com/qlproxy_external/issues/413.
If you are badly affected by this bug – write to email@example.com stating so and we will make a patch specifically for you. Sorry for the inconvenience and thanks a lot for Eric!
Diladele Development Team