WinUI 3 project created from a template runs fine in packaged mode ("MsixPackage"). However trying to run in unpackaged mode leads to an exception of loading required libraries. The easiest way to solve this is to make it build as self-contained application. To do so, add the following line into the project file in PropertyGroup section: <WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>