Maui FilePicker results in This platform does not support this file type.

Description

I am building a desktop app in .NET Maui which targets Windows and MacOS. When using the built-in FilePicker on Mac (Catalyst) I get the following error:

{System.PlatformNotSupportedException: This platform does not support this file type. at Microsoft.Maui.Storage.FilePickerFileType.GetPlatformFileType(DevicePlatform platform) at Microsoft.Maui.Storage.FilePickerFileType.get_Value() at Microsoft.Maui.S…}

I have tried multiple file types, including csv, jpg, text/csv but nothing works.

`public async Task ImportCSV() { try { var customFileType = new FilePickerFileType( new Dictionary<DevicePlatform, IEnumerable<string>> { { DevicePlatform.WinUI, new[] { “.csv” } }, { DevicePlatform.macOS, new[] {“csv”} } });

        PickOptions options = new()
        {
            PickerTitle = "Please select a csv file",
            FileTypes = customFileType
        };

        var file = await FilePicker.Default.PickAsync(options);

        if (file != null)
        {
            string filePath = AppStateService.fixMacFilePath(file.FullPath);

            AppStateService.AppState.csvFilePath = filePath;

            await InitiateCsvMapping();
        }
    }
    catch (Exception ex)
    {

    }
}`

Steps to Reproduce

1. Create a new Maui app.
2. Remove iOS and Android targets from project file.
3. Execute the shared code

Version with bug

6.0.400

Last version that worked well

Unknown/Other

Affected platforms

macOS

Affected platform versions

MacCatalyst 14.0

Did you find any workaround?

The documentation does say that I should “Enable iCloud capabilities” but does not provide any links or other information regarding this. I did some digging, and found some documentation that says that it necessary to do this via the Entitlements.plist file which I did but it seems to only be relevant when publishing your app to the App store which I am not during development. I don’t even care about iCloud right now. I just want to select a CSV file from my own desktop.

Relevant log output

{System.PlatformNotSupportedException: This platform does not support this file type.
   at Microsoft.Maui.Storage.FilePickerFileType.GetPlatformFileType(DevicePlatform platform)
   at Microsoft.Maui.Storage.FilePickerFileType.get_Value()
   at Microsoft.Maui.S…}

[cdavidyoung]

I found that if I use MacCatalyst instead of MacOS it works fine:

         var zipFileType = new FilePickerFileType(new Dictionary<DevicePlatform, IEnumerable<string>>
                                                  {
                                                     { DevicePlatform.iOS, new[] { "public.archive" } },
                                                     { DevicePlatform.Android, new[] { "application/zip" } },
                                                     { DevicePlatform.WinUI, new[] { "zip" } },
                                                     { DevicePlatform.MacCatalyst, new[] { "zip" } },
                                                        });
         var optionsZip = new PickOptions
            {
               PickerTitle = "Please select a previously backed up zip file",
               FileTypes = zipFileType
            };

[MGohil]

Providing supported file type options disables all those files in File Browser in Android. So, I am unable to pick those files. If I do not mention any file types (filePicker.PickAsync(null)) , it woks good, but shows all files.

I want to restrict to show only supported files to pick Ex. png, jpg, pdf.