src/vs/platform/files/browser/htmlFileSystemProvider.ts/HTMLFileSystemProvider/toFileSystemProviderError
class HTMLFileSystemProvider:	private toFileSystemProviderError(error: Error): FileSystemProviderError {
		if (error instanceof FileSystemProviderError) {
			return error; // avoid double conversion
		}

		let code = FileSystemProviderErrorCode.Unknown;
		if (error.name === 'NotAllowedError') {
			error = new Error(localize('fileSystemNotAllowedError', "Insufficient permissions. Please retry and allow the operation."));
			code = FileSystemProviderErrorCode.Unavailable;
		}

		return createFileSystemProviderError(error, code);
	}