Dear All:

I have a error ,I install sccm 2012 r2 and System Center 2012 R2 Endpoint Protection Depolye via unc and sccm

recent I find a server event viewer has issue error is below: 

            

Microsoft Antimalware has encountered an error trying to update signatures.
New Signature Version: 
Previous Signature Version: 1.203.2809.0
Update Source: Microsoft Update Server
Update Stage: Search
Source Path: http://www.microsoft.com
Signature Type: AntiVirus
Update Type: Full
User: NT AUTHORITY\SYSTEM
Current Engine Version: 
Previous Engine Version: 1.1.11903.0
Error code: 0x80248014
Error description: An unexpected problem occurred while checking for updates. For information on installing or troubleshooting updates, see Help and Support. 

Microsoft Antimalware has encountered an error trying to update the engine.
  New Engine Version: 1.1.12002.0
  Previous Engine Version: 1.1.11903.0
  Engine Type: Antimalware
  User: NT AUTHORITY\NETWORK SERVICE
  Error Code: 0x800700c1
  Error description: Microsoft Antimalware is not a valid Win32 application. 

 how I fix this error ?