XP-compatible Manifest

I got a report that one of my applications under Windows XP. It would just simply fail with "The application failed to start because the application configuration is incorrect. Reinstalling the application may fix this problem."

A bit deeper investigation into the Event Viewer discovered slightly different error description there "Syntax error in manifest or policy file "\QText.exe" on line 24. The element trustInfo appears as a child of element urn:schemas-microsoft-com:asm.v1^assembly which is not supported by this version of Windows."

Quick look into my manifest showed:

<trustInfo>
  <security>
    <requestedPrivileges>
      <requestedExecutionLevel level="asInvoker" uiAccess="false" />
    </requestedPrivileges>
  </security>
</trustInfo>

PPS: You can find schema at Microsoft's MSDN.

On first glance everything looked proper but next one brought obvious error. I was missing namespace declaration. Quick-fix was to just add it:

<trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
  <security>
    <requestedPrivileges>
      <requestedExecutionLevel level="asInvoker" uiAccess="false" />
    </requestedPrivileges>
  </security>
</trustInfo>

It was that easy.

I introduced this error some time ago when I was fixing high-DPI support. Manifest processing on anything higher than XP (e.g. even XP with some patches), is much more forgiving so this issue hasn't appeared much in the wild.

It simply goes to show that even most simple changes you do for one OS version might impact other. There is no substitute for actual testing.

PS: Just for reference, here is manifest I usually use:

<?xml version="1.0" encoding="utf-8"?>
<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
    <dependency xmlns="urn:schemas-microsoft-com:asm.v2">
        <dependentAssembly>
            <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*" />
        </dependentAssembly>
    </dependency>
    <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
        <security>
            <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
                <requestedExecutionLevel level="asInvoker" uiAccess="false" />
            </requestedPrivileges>
        </security>
    </trustInfo>
    <application xmlns="urn:schemas-microsoft-com:asm.v3">
        <windowsSettings xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">
            <dpiAware>true</dpiAware>
        </windowsSettings>
    </application>
    <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
        <application>
            <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />
            <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
            <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />
            <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />
            <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
        </application>
    </compatibility>
</assembly>

[2018-08-16: Added Windows 10 GUID.]