I am having the same problem. 

Dell Command | Update Version 2.2.0

Error Code: 3

Error: An unexpected validation error occurred.

OS: Windows 10

I've added multiple certificates including the ones available from the install packages.  Tried on and off out network here, with and without proxy.

Is there any verbose logging options to see where or what exactly is failing? The logs I've seen so far only have the same information, just in .xml format.

I am having the same issue.  Just curious, what version of Windows are you on?  I noticed that it happens with 1607 and works fine on 1511.  I've contacted Dell about this and they tried to recreate the problem but could not.

Mine is happening on 1511 as well. 

I just spent 2 hours on the phone with Dell.  Their fix is to download Precision Optimizer, because "its better".  Well, that also doesn't update drivers and comes up with a bland error "Error in checking doe update".  Good times... Maybe that will work for you, but I doubt it.

Interesting, I am also having issues on a Precision 5510.  But only on 1607, 1511 works fine for me. 

Its happening on a Dell Precision 5510 and no solution yet.

14393 here, no luck.  I've tried installing different root certs as well.  Still nogo.  Doesn't look like Dell's going to be much help....

I was looking at the 'Precession optimizer' It's listed as only being compatible with 2 systems....

Compatible Systems

I tested it again and I am still having the same problem. Dell Command Update appears to download the drivers, and then it tries to validate them, and then it says 'An unexpected validation error occurred.' and fails. 

I also tried with DUP 2.3.0

Has anyone else have any luck?