RE: Update failed to version Engine: 5301.4018 DAT: 5586.0000
I have exactly the same problem. About a 1/3rd of our servers are failing to update to the latest engine version.
The McScript.log shows :-
Copying Engine [IsEngineUnlocked] [NotifyFail] [NotifyingFailEngineDAT] Update failed to version Engine: 5301.4018 DAT: 5586.0000.
All other logfiles point to this script entry.
There are no engine updates available from McAfee's website for this version (unless you use ePo, which we don't) and the latest SDAT doesn't include this engine version either.
Incidentally, a workaround to just get the latest DAT version installed is to disable the 'Get newer detection engine and dats if available' option in the AutoUpdate Properties. This works for the current DAT versions, but who's to say how long this will work for, and the engine is still going to be out of date!
In my case, it turns out that the clients weren't at the latest patch level. Updating to patch 8 seems to have fixed this on at least one of my servers. I'll be checking others shortly.