The package uses an unsupported version of file makepri.exe
Partner Center shows this as a package acceptance validation error when you upload. The message names the version it found, like makepri.exe (10.0.26100.1), then lists the versions it allows and ends with "Please update your Visual Studio build tools and try again."
What it means
The package manifest records the build tools that made the package, including makepri.exe from the Windows SDK. Partner Center only accepts makepri.exe versions on its list. When a new Windows SDK comes out before Partner Center accepts it, every package built with it fails here.
That happened in 2024 with SDK 10.0.26100. A Microsoft moderator called it a known issue and said to go back to 10.0.22621. Developers reported in December 2024 that Partner Center then accepted 10.0.26100.
How to fix it
- Compare the version in the message with the allowed ranges listed after it.
- Build with Windows SDK build tools in an allowed range. If your project references the Microsoft.Windows.SDK.BuildTools NuGet package, set it to an allowed version. Developers on the GitHub issue fixed it by going back to 10.0.22621.3233, or by removing that package.
- Don't edit the version in the manifest and zip the package back up. One developer who tried it got "APPX_E_INVALID_BLOCKMAP - The package's block map is invalid" instead. Rebuild with your packaging tool.
- Upload the rebuilt package.
Sending the fixed update with StoreFast
StoreFast can send your next update to Partner Center from a dashboard, CI or a coding agent.
Sources
Facts about Microsoft's tools were checked against these pages on October 16, 2026.