UWP App: Error in WACK - Unable to fetch list of approved APIs

Walter Humfeld 0

I've written a UWP app in C#.NET. I've tested it, and want to publish it to the App Store, so I need to run the Windows App Certification Kit (WACK) on it. Most of the tests pass, but the Supported API test fails consistently, always saying:

"The supported APIs test detected the following errors: Unable to get the list of approved APIs."

Note that this doesn't mean that I'm using any unapproved APIs. In fact, near as I can tell, WACK hasn't checked the APIs I'm using at all, because it's unable to get the list of what I -can-use. This seems to be a clear bug in WACK - how can I pass the test if it can't figure out what the 'passing' and 'failing' criteria would be and actually run the test?

Note that this has occurred in the following conditions:

- VPN on

- VPN off

- run WACK as Administrator

- run WACK not as Administrator

What steps can I take to resolve this error and ensure WACK can fetch the list of approved APIs?

Here's the relevant bit from WACK's output:

FAILED

Supported APIs

Error Found: The supported APIs test detected the following errors:

    Unable to get the list of approved APIs.

Impact if not fixed: Using an API that is not part of the Windows SDK for Microsoft Store apps violates the Microsoft Store certification requirements.

How to fix: Review the error messages to identify the API that is not part of the Windows SDK for Microsoft Store apps. If the DLL listed is an allowable redistributable from a NuGET package, SDK or other toolkit, did you forget to add the DLL to your app? Please note, apps that are built in a debug configuration or without .NET Native enabled (where applicable) can fail this test as these environments may pull in unsupported APIs. Retest your app in a release configuration, and with .NET Native enabled if applicable. See the link below for more information: [link]

I notice that the 'How to fix' section says to identify the API that's not part of the Windows SDK... but the error message doesn't identify any APIs at all.

Here's some information about my app and system from WACK:

App Architecture: x64

Kit Version: 10.0.26100.1742

OS Version: Microsoft Windows 10 Pro (10.0.19045.0)

OS Architecture: x64

Some details about the Windows SDK from my Project Properties:

- Target Version is Build 26100 

- Min version is Build 17763

I tried putting the Min Version to 22000 (first Windows 11 build), but I'm running Windows 10, so WACK didn't run all the tests. I tried various Windows 10 options for the Minimum version, and just stuck with the one I'd originally been using, 17763.

Roy Li - MSFT 33,371 Reputation points Microsoft Vendor

2024-10-30T02:41:38.45+00:00

Is there any DLL or other libraries that you are using your app? Are you just using WinRT API in your app or you are using some Win32 API in your app? Not all the Win32 API are allowed to use in UWP. If you did use some Win32 API in your app or in the DLLs or libraries, please make sure you are only Win32 API from this document: Win32 and COM APIs for UWP apps.

Besides, the local WACK test is optional. If you upload your app to the Store, there will be an online WACK test for your package and that result will be more accurate.
Walter Humfeld 0 Reputation points

2024-10-30T21:02:32.3966667+00:00

Hi @Roy Li - MSFT thanks for responding. I'm using the following References (see image below), the ones with the blue icons which I've gotten through NuGet.

Thanks for the link to the 'allowed stuff' page; as I'm looking through the API names, none of them look familiar, but the list is huge, so it's possible that I just haven't gotten to anything I've used.

Looking at the list, I don't know how to interpret it to tell if I'm using Win32 APIs in the app; for example, I don't see "UnhandledExceptionEventHandler" in the list, and I've called "Windows.UI.Xaml.UnhandledExceptionEventHandler(param)" in one place... is that disallowed? My 'using' blocks in my .cs files tend to be pretty lengthy; are those the places I'd look to see if I'm using disallowed APIs? I don't seen "Xaml" in the list either, so does that imply that I can't use "Windows.UI.Xaml"? If that's the case, what alternative could possibly be used instead, as that's pretty fundamental to a lot of UI design?

I'm also not sure how relevant the answer to that question is, if WACK can't fetch the list of approved APIs in the first place. It's not saying that I'm using anything that's not allowed, it's saying that it can't even determine what's allowed and what's not.

Thanks again for your help; I feel like there's one or two points of terminology that I'm not understanding very well, and things will fall into place once that confusion is cleared up.
Walter Humfeld 0 Reputation points

2024-10-30T21:02:57.3833333+00:00

Hi @Roy Li - MSFT thanks for responding. I'm using the following References (see image below), the ones with the blue icons which I've gotten through NuGet.

Thanks for the link to the 'allowed stuff' page; as I'm looking through the API names, none of them look familiar, but the list is huge, so it's possible that I just haven't gotten to anything I've used.

Looking at the list, I don't know how to interpret it to tell if I'm using Win32 APIs in the app; for example, I don't see "UnhandledExceptionEventHandler" in the list, and I've called "Windows.UI.Xaml.UnhandledExceptionEventHandler(param)" in one place... is that disallowed? My 'using' blocks in my .cs files tend to be pretty lengthy; are those the places I'd look to see if I'm using disallowed APIs? I don't seen "Xaml" in the list either, so does that imply that I can't use "Windows.UI.Xaml"? If that's the case, what alternative could possibly be used instead, as that's pretty fundamental to a lot of UI design?

I'm also not sure how relevant the answer to that question is, if WACK can't fetch the list of approved APIs in the first place. It's not saying that I'm using anything that's not allowed, it's saying that it can't even determine what's allowed and what's not.

Thanks again for your help; I feel like there's one or two points of terminology that I'm not understanding very well, and things will fall into place once that confusion is cleared up.
Roy Li - MSFT 33,371 Reputation points Microsoft Vendor

2024-10-31T01:13:11.9433333+00:00

I've called "Windows.UI.Xaml.UnhandledExceptionEventHandler(param)" in one place... is that disallowed?

Supported API test only checks for Win32 APIs that are not allowed for UWP apps. UWP Xaml code are WinRT APIs and allowed to use. The Test is specific to the Win32 APIs used in your app include the NuGet Packages. That's why I shared the document about the Win32 APIs that could be used in UWP apps.

You could also get the test details about Supported API test here: https://learn.microsoft.com/en-us/windows/uwp/debug-test-perf/windows-app-certification-kit-tests#supported-api-test

As I mentioned previously, you will need to check the Win32 APIs that used in your app or maybe used in the NuGet Packages. UWP APIs are WinRT API and will not fail in this test.

If you don't use any Win32 API in your app, then the issue might be related to the NuGet Packages.

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