该应用可能已卸载。卸载是一项新的iOS 11功能，允许用户或iOS系统删除应用程序以释放空间而不删除任何配置或设置。

The app may have been offloaded. Offloading is a new iOS 11 feature that allows user or the iOS system to remove an app to free up space without deleting any of its configurations or settings.

要知道是否有应用程序已卸载，它在其名称前面显示一个小云图标。

To know if an app has been offloaded, it displays a small cloud icon in front of its name.

打开已卸载的应用程序时，Apple会尝试从App Store下载该应用程序。由于它是App Store上没有的企业应用程序，因此无法下载并显示此错误。

When opening an offloaded app, Apple tries to download the app back from App Store. Since it's an enterprise app that's not available on App Store, it can't download it and shows up this error.

解决方案？好吧，正如Apple所说：这个应用程序没有从App Store安装，必须手动重新安装。再次从托管位置下载企业应用程序并进行安装。

The solution? Well, just what Apple says: "This app was not installed from the App Store and must be reinstalled manually". Download the enterprise app again from where it's hosted and install it.