Windows platform in MAUI: Operation is not valid due to the current state of the object

[erossini]

Hi,
I'm using your component in NET 8 MAUI and it is working fine for all the platforms. Now, I started a new project with NET 9 MAUI and copied the class to connect to the APIs. I use the MonkeyCache.FileStore. In the Windows application, when I try to save or clean the cache for example using this command

Barrel.Current.EmptyExpired();

I get an error

System.InvalidOperationException: 'Operation is not valid due to the current state of the object.'

Is there any particular configuration to use for Windows?

[AndreKraemer]

Starting with .NET MAUI 9, Windows App run as unpackaged apps. When running as non-packaged/unpackaged on Windows, MonkeyCache.FileStore tries to access Windows.Storage.ApplicationData.Current, which throws InvalidOperationException because this WinRT API is only available in packaged (MSIX) apps.

The solution is to run as a packaged app. You can achive that by changing your launchSettings.json file to this:

{
  "profiles": {
    "Windows Machine": {
      "commandName": "MsixPackage",
      "nativeDebugging": false
    }
  }
}

The important line is "commandName": "MsixPackage", which is '"commandName": "Project" in the new template.

In addition you need to comment this entry in your csproj file

None