files-community/Files · warning · NotSupportedException

Specified method is not supported.

Error message

Specified method is not supported.

What it means

Thrown by VirtualStorageFolder.CreateItemQuery as NotSupportedException. VirtualStorageFolder is a lightweight, in-memory BaseStorageFolder that does not back a real Windows.Storage query. It does not implement the legacy StorageItemQueryResult surface; only the 'WithOptions' variant is supported (it returns a BaseStorageItemQueryResult).

Source

Thrown at src/Files.App/Utils/Storage/StorageItems/VirtualStorageFolder.cs:106

		public override IAsyncOperation<BaseStorageFolder> CreateFolderAsync(string desiredName, CreationCollisionOption options)
			=> throw new NotSupportedException();
		public override IAsyncOperation<BaseStorageFolder> MoveAsync(IStorageFolder destinationFolder) => throw new NotSupportedException();
		public override IAsyncOperation<BaseStorageFolder> MoveAsync(IStorageFolder destinationFolder, NameCollisionOption option) => throw new NotSupportedException();

		public override IAsyncAction RenameAsync(string desiredName)
			=> RenameAsync(desiredName, NameCollisionOption.FailIfExists);
		public override IAsyncAction RenameAsync(string desiredName, NameCollisionOption option)
			=> throw new NotSupportedException();

		public override IAsyncAction DeleteAsync()
			=> throw new NotSupportedException();
		public override IAsyncAction DeleteAsync(StorageDeleteOption option) => DeleteAsync();

		public override bool AreQueryOptionsSupported(QueryOptions queryOptions) => false;
		public override bool IsCommonFileQuerySupported(CommonFileQuery query) => false;
		public override bool IsCommonFolderQuerySupported(CommonFolderQuery query) => false;

		public override StorageItemQueryResult CreateItemQuery() => throw new NotSupportedException();
		public override BaseStorageItemQueryResult CreateItemQueryWithOptions(QueryOptions queryOptions) => new(this, queryOptions);

		public override StorageFileQueryResult CreateFileQuery() => throw new NotSupportedException();
		public override StorageFileQueryResult CreateFileQuery(CommonFileQuery query) => throw new NotSupportedException();
		public override BaseStorageFileQueryResult CreateFileQueryWithOptions(QueryOptions queryOptions) => new(this, queryOptions);

		public override StorageFolderQueryResult CreateFolderQuery() => throw new NotSupportedException();
		public override StorageFolderQueryResult CreateFolderQuery(CommonFolderQuery query) => throw new NotSupportedException();
		public override BaseStorageFolderQueryResult CreateFolderQueryWithOptions(QueryOptions queryOptions) => new(this, queryOptions);

		public override IAsyncOperation<StorageItemThumbnail> GetThumbnailAsync(ThumbnailMode mode)
			=> Task.FromResult<StorageItemThumbnail>(null).AsAsyncOperation();
		public override IAsyncOperation<StorageItemThumbnail> GetThumbnailAsync(ThumbnailMode mode, uint requestedSize)
			=> Task.FromResult<StorageItemThumbnail>(null).AsAsyncOperation();
		public override IAsyncOperation<StorageItemThumbnail> GetThumbnailAsync(ThumbnailMode mode, uint requestedSize, ThumbnailOptions options)
			=> Task.FromResult<StorageItemThumbnail>(null).AsAsyncOperation();
	}
}

View on GitHub (pinned to 68c68a58d4)

Solutions

1. Use CreateItemQueryWithOptions(queryOptions) instead, which is supported and returns a BaseStorageItemQueryResult.
2. Check the folder type before calling; for VirtualStorageFolder, prefer GetItemsAsync directly.
3. Catch NotSupportedException and fall back to the WithOptions overload or direct enumeration.
4. If you must support the plain query, subclass VirtualStorageFolder and override CreateItemQuery to build a result over GetItemsAsync.

Example fix

// before
var query = folder.CreateItemQuery();

// after
var query = folder.CreateItemQueryWithOptions(new QueryOptions());
// or enumerate directly
var items = await folder.GetItemsAsync();

// Prefer the supported WithOptions query over the plain query.
BaseStorageItemQueryResult result =
    folder is VirtualStorageFolder
        ? folder.CreateItemQueryWithOptions(new QueryOptions())
        : folder.CreateItemQuery();

static bool SupportsPlainItemQuery(BaseStorageFolder f) => f is not VirtualStorageFolder;

try { var q = folder.CreateItemQuery(); }
catch (NotSupportedException) { var q = folder.CreateItemQueryWithOptions(new QueryOptions()); }

When it happens

Trigger: Calling CreateItemQuery() on any VirtualStorageFolder instance. This happens when code requests the non-options query API, e.g. older WinRT-style enumeration or a consumer that does not use CreateItemQueryWithOptions.

Common situations: Third-party or legacy code calling the plain CreateItemQuery; search/indexing features that fall back to the parameterless query; generic algorithms that enumerate all query-creation entry points.

Related errors

• Copying folders is not supported.
• File already exists.
• Couldn't generate unique name. File skipped.
• File creation failed.
• Directory already exists.

AI-assisted analysis of files-community/Files@68c68a58d4 (2026-08-13). Data as JSON: /api/errors/a1e031ad0d2af3ac. Report an issue: GitHub.