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

Question

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

Nallamuthu Sundhararajan 25

Hi all,
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!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!

Junjie Zhu - MSFT 21,651 Reputation points

2025-03-31T07:11:32.29+00:00

Hello,

Welcome to Microsoft Q&A!

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."

May I ask at which step you get this error? Which step exactly after opening Project->Publish->Create App Packages?

Thank you
Nallamuthu Sundhararajan 25 Reputation points

2025-04-01T05:36:16.98+00:00

Hi @Junjie Zhu - MSFT

We thank you for your response. We attempted to use the Windows App Certificate Kit to validate the package. The previously mentioned problem is being thrown out.
Junjie Zhu - MSFT 21,651 Reputation points

2025-04-01T06:44:34.17+00:00

Hi @Nallamuthu Sundhararajan ,

Could you please share your detailed steps and screenshots to help us further check the problem for you? Is it "associate with the store"? Or just a sideload package?

Thank you.
Nallamuthu Sundhararajan 25 Reputation points

2025-04-03T11:22:13.7+00:00

Hi @Junjie Zhu - MSFT

I apologize for the delay in responding, and when I test the package using the Windows App Cer Kit, please refer to the attached image reference for the Package Digital Sign issue.

Additionally, this app has already been released in the store, and I'm currently checking the most recent version. obtaining the most recent functioning flow verification locally.

1 answer

Your answer

Junjie Zhu - MSFT 21,651 Reputation points

2025-03-31T07:11:32.29+00:00

Hello,

Welcome to Microsoft Q&A!

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."

May I ask at which step you get this error? Which step exactly after opening Project->Publish->Create App Packages?

Thank you
Nallamuthu Sundhararajan 25 Reputation points

2025-04-01T05:36:16.98+00:00

Hi @Junjie Zhu - MSFT

We thank you for your response. We attempted to use the Windows App Certificate Kit to validate the package. The previously mentioned problem is being thrown out.
Junjie Zhu - MSFT 21,651 Reputation points

2025-04-01T06:44:34.17+00:00

Hi @Nallamuthu Sundhararajan ,

Could you please share your detailed steps and screenshots to help us further check the problem for you? Is it "associate with the store"? Or just a sideload package?

Thank you.
Nallamuthu Sundhararajan 25 Reputation points

2025-04-03T11:22:13.7+00:00

Hi @Junjie Zhu - MSFT

I apologize for the delay in responding, and when I test the package using the Windows App Cer Kit, please refer to the attached image reference for the Package Digital Sign issue.

Additionally, this app has already been released in the store, and I'm currently checking the most recent version. obtaining the most recent functioning flow verification locally.

Answer 1

Harry Vo (WICLOUD CORPORATION) 405 Microsoft External Staff

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!

Harry Vo (WICLOUD CORPORATION) 405 Reputation points Microsoft External Staff

2025-07-16T06:09:43.46+00:00

Hi @Nallamuthu Sundhararajan ,

Have you solved your issue yet? Let me know if you have any question! Thank you!

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

1 answer

Your answer