My windows user name is "Bj枚rn", and hence contains a non-ASCII character. When I try to install any package using winget, I receive an error message similar to the following one:
"C:\Users\Bj脙露rn\AppData\Local\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\TempState\WinGet\gimp.gimp.2.10.18.exe" konnte nicht gefunden werden. Stellen Sie sicher, dass Sie den Namen richtig eingegeben haben und wiederholen Sie den Vorgang.
The specified path indeed does not exist. Replacing "Bj脙露rn" with my correct username, "Bj枚rn", though, leads to the correct file downloaded by winget.
cmd.winget install gimp.gimp -ewinget should download the installer and execute it.
winget downloads the installer, but fails to execute it, because it uses an invalid path for running the downloaded file. This leads to the following error message in a message box window:
"C:\Users\Bj脙露rn\AppData\Local\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\TempState\WinGet\gimp.gimp.2.10.18.exe" konnte nicht gefunden werden. Stellen Sie sicher, dass Sie den Namen richtig eingegeben haben und wiederholen Sie den Vorgang.
On the command line, I get this message:
Installer failed with exit code: 1223
[winget --info]
Windows Package Manager v0.1.41331 Vorschau
Copyright (c) Microsoft Corporation. All rights reserved.
Windows: Windows.Desktop v10.0.18363.836
Package: Microsoft.DesktopAppInstaller v1.0.41331.0
Got this too :

me too (my username is Krist贸f)
Any workaround?
We plan to fix this in v0.2 milestone. Thanks.
The fix should have been included with release v0.2.2521. Below is a working snapshot.
Please feel free to reopen the issue if the fix does not work as expected.
Most helpful comment
We plan to fix this in v0.2 milestone. Thanks.