Hi All,

I've an issue during installation of .NET Framework 3.5 via Powershell:

PS C:\Users\treviss> Install-WindowsFeature NET-Framework-Core Source D:\Sources\
Install-WindowsFeature :
 The request to add or remove features on the specified server failed.Installation of one or more roles, role services,
 or features failed.The source files could not be downloaded.Use the "source" option to specify the location of the
 files that are required to restore the feature. 
For moreinformation on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077. 
Error: 0x800f0906At line:1 char:1+ Install-WindowsFeature NET-Framework-Core Source D:\Sources\
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~    + CategoryInfo          : InvalidOperation: 
(@{Vhd=; Credent...Name=localhost}:PSObject) [Install-WindowsFeature],    Exception    + FullyQualifiedErrorId :
 DISMAPI_Error__Cbs_Download_Failure,Microsoft.Windows.ServerManager.Commands.AddWindowsF   eatureCommand

I tried all solution I've found. 
Execute by Powershell, DISM...
Disable download via WSUS by GPO...


.Net Framework 4.5 is already installed. 
Do you think I have to uninstall 4.5 before install 3.5? 


Thanks.

Kind Regards,
Stephane

Follow https://support.microsoft.com/en-us/kb/2734782

(If this dos not help, try removal tool from Aaron Stebner and reinstall Framework. )

M.

NO - do not uninstall 4.5.

I have not had any issues with this recently, but during the release candidate phase I remember having the issue once in a while.  At that point I got around the issue by copying the \sxs directory from the distribution media to a local temporary directory and point the -Source parameter at that.

Also, I've always used \sources\sxs instead of just specifying \sources as the -Source parameter when trying to use the distribution media.

Hello,

One thing to keep in mind, the sources folder has to be in sync with the servicing level of the OS.

So if you have installed updates from Windows Updates, to use the sources folder, it would have be updated to the same servicing level.  Or you could point to another server's WinSXS folder that is at the same servicing level that has .NET 3.5 already installed.

Hi,

Based on my experience, if you have intalled security update 2966827(Windows Server 2012) or 2966828(Windows Server 2012 R2), then it may fail when enabling the .NET Framework 3.5 Windows feature in Windows Server 2012:

https://support.microsoft.com/en-us/kb/3005628

Please also check if you have installed that update. If yes, please uninstall it and restart to see if the issue persists.

Best regards,

Susie