Cannot install App Package - This .appinstaller file is using a new schema ...

[chrisDK1977]

I get the error:
This .appinstaller file is using a new schema which is not valid on this OS version. Please update to the latest version of Windows 10.

but Windows update does show me that my system is "Up to date".

[YehudaKremer]

https://docs.microsoft.com/en-us/windows/msix/app-installer/troubleshoot-appinstaller-issues

[khanliKU]

I got the same error when I ran "flutter pub run msix:publish"

My OS build is 19042.1586. The page says:

"Windows 10 1909 and earlier:
The device must be enabled for Developer Mode or Sideloading apps. See Enable your device for development to learn more."

Developer Mode was already enabled for me.

However I was able install my app using the msix I created by running "flutter pub run msix:create"

FYI

[carminechoi]

Changing the xmlns in the appinstaller from "http://schemas.microsoft.com/appx/appinstaller/2021" to "http://schemas.microsoft.com/appx/appinstaller/2018" fixed it for me

[jhiggs15]

Anyone know if there is a way to set xmlns from msix_config?

[YehudaKremer]

Hello

I publish a new version (3.6.3) with @carminechoi suggestion, thank you.