Dell Precision M6400 installer issues (stop sign)

At first the installer would show up with the Apple logo and then reboot, I've been following this thread (http://www.tonymacx86.com/threads/d...-into-installer-el-capitan-unibeast-6.176092/) and using the HD4000 plist the progress bar appears, it loads, and then a stop sign appears, the M6400 doesn't seem to be well documented in the OSX community so I am not aware of there being any DSDT to work from, so I am bit stuck what to try next.

I've...

Dell Precision M6400 installer issues (stop sign)