FEP Error. Last Enforcement Error Code 0x80070643

Question

I have a Windows 2012 server running SCCM 2012 SP1 CU4.  I use it primarily for Endpoint Protection and Windows Updates.
I have several Automatic Update Rules to deploy Endpoint definitions
every night.
I was going through some of the Deployments (to check for errors and such) when I saw that almost all of them had errors.  Under
Monitoring --> Deployments I click on the Error
tab and what I see is this:  Last Enforcement Error Code: 0X80070643 and it was dated 5/7/2014.
My own PC was listed as having this error so I opened the System Center Endpoint Protection application.  I clicked on the
Update tab and it shows Up to date with "Definitions last updated:  5/11/2014."
Is this something I should worry about since the "successful" date is
after the "error" date?  On my client PC, I looked at the
EndpointProtectionAgent.log file, but did not see any errors.  Are there other log files I should look at to find more details about the error?
I want to add that I also see this entry in the Event Viewer (under Event Viewer --> Windows Logs --> System):
Installation Failure: Windows failed to install the following update with error 0x80070643: Definition Update for Microsoft Endpoint Protection - KB2461484 (Definition 1.173.1491.0).
There are other successful messages in the Event Viewer after that message.  Maybe just something wrong with that particular update on that particular date??
Thanks in advance!

Answer 1

Thanks for the reply.  I saw that thread, but it does not apply to my particular issue. 
I have already gotten Forefront Endpoint Protection installed successfully across my enterprise.  My problem is with a definition update.