Installing .NET Framework 3.5 on Server 2019 fails

By | February 16, 2019

By default, .NET Framework 3.5 is not installed on Server 2019 and also the sources are not getting installed. If you open Roles and Features and select the feature and start the installation you are likely to get an error message (0x800F0950). The same is true when you download it from the Microsoft content server and try to install it by dism or Enable-WindowsOptionalFeature.

You have to take the sources from the sources\sxs folder of the Server 2019 iso file. If you have the installation DVD still inserted (which is usually the case if you set up a virtual machine) you can enter the path (probably d:\sources\sxs) on the Confirmation page of the Add-Roles-And-Features-wizard by selecting Specify an alternate source path.

Alternatively, mount the iso by double-clicking it (Win8 or later), copy the 2 microsoft-windows-netfx3… cab files in the folder sources\sxs and paste them to your server. Afterwards, you can call

dism /online /Add-Package /PackagePath:[sourcepath]\

34 thoughts on “Installing .NET Framework 3.5 on Server 2019 fails

  1. jim

    was struggling with this, trying to install net 2.5 on server 2019. very helpful thanks

  2. imran

    or you can do the select alternative source and give the parth.

  3. MeMe

    Thank you so much for taking the time to write this. V. helpful.

  4. Tekniqueman

    Thanks for pointing out that you need to use the 2 files from the folder sources\sxs on an ISO with server 2019 on, and not to use the ordinary installationfiles for .net 3.5 you can download from Microsoft.
    Strange they are not copied to the sxs folder on the server during the server’s installation.

  5. Matt Sousa

    I mounted my disk image but in this folder specifically I can’t find these cab files…anyone with the same problem?

    1. max Post author

      You are looking at [drive]\sources\sxs of the installation iso, right? The file should be in there.

  6. Derik Meeks

    Thanks for this post! The solution worked as directed.

  7. curtisy

    Thanks! Worked as expected. I used the copy files from ISO to another server and install via dism method.

  8. true

    I don’t have a disc or a iso how can I get the iso downloaded from the web? Or these two files rather.


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