Unreal Engine 4 is available for Win10 UWP app dev now

[anonymous_user_582995091 (anonymous_user_58299509)]

To confirm: when you get this error you’re attempting to build/run in Visual Studio, not in the Unreal Editor?

Meanwhile I remain perplexed. The AppxManifest.xml file you provided validates for me in VS using the same schema set that UnrealBuildTool applies Specifically for the 10586 SDK these are:
Windows Kits\10\Include\10.0.10586.0\winrt\UapManifestSchema.xsd
Windows Kits\10\Include\10.0.10586.0\winrt\FoundationManifestSchema.xsd
Windows Kits\10\Include\10.0.10586.0\winrt\AppxManifestTypes.xsd
Windows Kits\10\Include\10.0.10586.0\winrt\AppxManifestSchema2010_v2.xsd
Windows Kits\10\Include\10.0.10586.0\winrt\AppxManifestSchema2013.xsd
Windows Kits\10\Extension SDKs\WindowsMobile\10.0.10586.0\Include\WinRT\AppxPhoneManifestSchema2014.xsd

Additionally I’ve confirmed that I’m able to manually run makepri against that file + a Resources directory and get valid output. I do see that your folder contains a resources.pri, which suggests that makepri succeeded at some point. Any idea what might have changed?

> makepri createconfig /cf priconfig.xml /dq en /o /pv 10.0.0
Writing PRI config file to priconfig.xml …
Successfully Completed
> makepri /pr . /cf priconfig.xml /mn AppxManifest.xml /il resindexlog.xml /o /of resources.pri
MakePri: warning: Output location of PRI file(s) is detected to be under the project root. If previously generated PRI file(s) are present, these may be re-indexed and lead to unexpected results.
Index Pass Completed.
Language Qualifiers: en
Scale Qualifiers: 100

Finished building
Version: 1.0
Resource Map Name: UE4Game
Named Resources: 8

Resource File: resources.pri
Version: 1.0
Resource Candidates: 14
Language Qualifiers: en
Scale Qualifiers: 100

Successfully Completed