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Support Needed: Error 0x800B0100 - App Package Must Be Digitally Signed

Nallamuthu Sundhararajan 25 Reputation points
2025-03-28T12:23:39.7+00:00

Hello Community,

I'm currently facing an issue while creating a UWP package in Unity, and I keep encountering the error 0x800B0100. The error message states, "The app package must be digitally signed for signature validation."

Here are the details of my setup:

Unity Version: 6.0.1f1

Target Platform: UWP

Visual Studio Version: Visual Studio Community 2022 (17.11.5)

Windows Version: Windows 11 (23H2)

What I've Tried:

Signing the App Package: I checked the project properties in Visual Studio to ensure that I selected a valid certificate for signing the app, but the error persists.

Certificate Validity: I verified the certificate used for signing and confirmed that it is valid and not expired.

Recreating the App Package: I attempted to create the app package again from scratch, ensuring that I followed the signing process closely.

Running the Windows App Certification Kit: I ran my app through WACK, but I didn't find any significant issues.

Request for Help:

I would greatly appreciate any insights or suggestions on how to resolve this issue. Has anyone else experienced this error, and if so, what steps did you take to fix it? Any help would be immensely valuable!

Thank you in advance for your assistance!

Developer technologies | Universal Windows Platform (UWP)
Answer recommended by moderator
  1. Nallamuthu Sundhararajan 25 Reputation points
    2025-10-10T05:16:06.9066667+00:00

    Hi all,

    I apologize for the delay in responding...

    Analyzing the issue, I found that the root cause was the package not being digitally signed properly. To resolve this, I directly signed the package using the certificate with the following command:

    text
SignTool sign /fd sha256 /a /f "FilePath.pfx" /p password "UWP Package Installable file path.msix"

    /fd sha256 specifies the file digest algorithm.

    /a automatically selects the best signing certificate.

    /f "FilePath.pfx" points to the certificate file.

    /p password is the password for the certificate.

    The last argument is the path to the UWP package (.msix file).

    This method successfully fixed the digital signature issue, allowing the package to be accepted by the Microsoft Store.

    Feel free to ask if you need more details on this or related steps!

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  1. Harry Vo (WICLOUD CORPORATION) 3,355 Reputation points Microsoft External Staff Moderator
    2025-07-11T03:22:40.9466667+00:00

    Hi @Nallamuthu Sundhararajan ,

    Thanks for sharing the details! I suspect that the signing process in Unity's UWP export pipeline may not be correctly applying the certificate.

    Just one quick thing to double-check—when you exported the UWP project from Unity and created the final package, ensure that the signing step was applied during that export process!

    Sometimes selecting a certificate in Visual Studio isn't enough if the actual signing doesn’t happen at the packaging stage. It might be worth reviewing the export workflow to make sure the digital signature is embedded properly during that step.

    Let me know if this fixes your problem!

    Thank you!

  2. Suraj Kamya 5 Reputation points
    2025-08-28T13:36:23.87+00:00

    Is it resolved or still pending

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