@Rafael Dipold have you done something different than in that article? It isn't working for me. I didn't used Delphi IDE because it's calling makeappx.exe with /f (mapping file) and I used /d (content directory) I have the same file with two names in Assets: Logo44x44.png and Logo44x44.targetsize-44_altform-unplated.png The Root folder is every time new created and filled with all necessary files then:   C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root>"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\makepri.exe" createconfig /cf priconfig.xml /dq en-US       
'Platform (pv)' not specified. Default is Windows 10. Writing PRI config file to priconfig.xml ... Successfully Completed
C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root>"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\makepri.exe" new /pr "C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root" /cf priconfig.xml
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. AlternateForm Qualifiers: UNPLATED TargetSize Qualifiers: 150,44   Finished building Version: 1.0 Resource Map Name: winarhi.winarhi15s Named Resources: 27   Resource File: resources.pri Version: 1.0 Resource Candidates: 29 AlternateForm Qualifiers: UNPLATED TargetSize Qualifiers: 150,44   Successfully Completed   C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root>"C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\makeappx.exe" pack /d "C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root" /p "C:\Delphi\WA15\WinArhi\!Executabil Showroom\!FINAL\WinArhi_15_Showroom.msix"
Microsoft (R) MakeAppx Tool Copyright (C) 2013 Microsoft.  All rights reserved.   The path (/p) parameter is: "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\!FINAL\WinArhi_15_Showroom.msix" The content directory (/d) parameter is: "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root" Enumerating files from directory "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root" Packing 30 file(s) in "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root" (content directory) to "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\!FINAL\WinArhi_15_Showroom.msix" (output file name). Memory limit defaulting to 5368131584 bytes. Memory limit defaulting to 4294967296 bytes. Using "\\?\C:\Delphi\WA15\WinArhi\!Executabil Showroom\UWP\Root\AppxManifest.xml" as the manifest for the package. ....... ....... Package creation succeeded.