An app or app extension attempted to connect to a background session that is already connected to a process.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
This error can occur when both an app and an app extension attempt to use a background session at the same time.
A connection was attempted while a phone call was active on a network that doesn’t support simultaneous phone and data communication, such as EDGE or GPRS.
A request for an FTP file resulted in the server responding that the file is not a plain file, but a directory.
The URL Loading System encountered an error that it can’t interpret.
A server reported that a URL has a non-zero content length, but terminated the network connection gracefully without sending any data.