Attempting to install a created App Package fails with error code 0x8000FFFF among other issues.

New Contributor

After creating an App Package from a WinUI 3 project, attempting to install it using the created .msix file results in the error code: 0x8000FFFF. Installing the application using "Install.ps1" and enabling developer mode works but is not reasonable for end users. Also, when setting "Create App Bundle" to "Never", an "Index.html" file and subsequent .appinstaller file are never created even though the output window specifies that it has. Furthermore, if automatic updates were selected and "Copy and Close" is selected, the files are never copied even though the output window again specifies that the operation succeeded.


This is the error that I get:

App installation failed with error message: Deployment Add operation with target volume C: on Package ID_OF_MY_APP_1.0.0.0_x64__wtta9nmxf3nwp from: (NAME_OF_MY_APP_1.0.0.0_x64.msix) failed with error 0x8000FFFF. See for help diagnosing app deployment issues. (0x8000ffff)


This is the process I'm going through:

  1. Create a new WinUI 3 C# project using "Template Studio for WinUI (C#)"
  2. Right click on the project and select "Package and Publish" => "Create App Packages..."
  3. Select "Enable Automatic Updates"
  4. Select "Always" under "Generate app bundle:"
  5. Set a local folder on your computer as the "Installer Location:"
  6. Create the app and select "Copy and Close".
  7. Navigate to the location listed.
  8. Observe that there is no "index.html" or .appinstaller file created.
  9. Attempt to install the .msix file.
  10. Observe error 0x8000FFFF.
  11. Navigate to the Installer location.
  12. Observe that the folder is empty.

Is this a known issue? If so, is there a workaround? I'm trying to distribute the app I've made but the only way I've been able to do so using MSIX is the PowerShell script and enabling developer mode which is no good for end users.

3 Replies

Hi @BR_Red_Panda,


Thank you for reaching out regarding your issue concerning the creation of an MSIX packaged app using the WinUI 3 project. 


With regards to the error you are receiving with the install, can you confirm that the MSIX packaged app has been signed using a code signing certificate that is trusted by the device?

@Roy_MacLachlan, Yes, I created and installed a certificate as part of the packaging process.

best response confirmed by Roy_MacLachlan (Microsoft)

Hi @BR_Red_Panda,

My initial thoughts on this, is that there is an issue with the certificate used to sign the app. But as you've confirmed, the Certificate has been installed on the system. I'd also like to confirm that it is installed in the Trusted People certificate store?

If it is, please submit a feedback hub submission by pressing [Windows Key]+[F], recording your install experience and then after submitting it, please share with me in this post, or in direct messaging information about the feedback item.