NSURLErrorAppTransportSecurityRequiresSecureConnection
App Transport Security disallowed a connection because there is no secure network connection.
NSURLErrorBackgroundSessionInUseByAnotherProcess
An app or app extension attempted to connect to a background session that is already connected to a process.
NSURLErrorBackgroundSessionRequiresSharedContainer
The shared container identifier of the URL session configuration is needed but hasn’t been set.
NSURLErrorBackgroundSessionWasDisconnected
The app is suspended or exits while a background data task is processing.
NSURLErrorBadServerResponse
The URL Loading System received bad data from the server.
NSURLErrorBadURL
A malformed URL prevented a URL request from being initiated.
NSURLErrorCallIsActive
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.
NSURLErrorCancelled
An asynchronous load has been canceled.
NSURLErrorCannotCloseFile
A download task couldn’t close the downloaded file on disk.
NSURLErrorCannotConnectToHost
An attempt to connect to a host failed.
NSURLErrorCannotCreateFile
A download task couldn’t create the downloaded file on disk because of an I/O failure.
NSURLErrorCannotDecodeContentData
Content data received during a connection request had an unknown content encoding.
NSURLErrorCannotDecodeRawData
Content data received during a connection request couldn’t be decoded for a known content encoding.
NSURLErrorCannotFindHost
The host name for a URL couldn’t be resolved.
NSURLErrorCannotLoadFromNetwork
A specific request to load an item only from the cache couldn't be satisfied.
NSURLErrorCannotMoveFile
A downloaded file on disk couldn’t be moved.
NSURLErrorCannotOpenFile
A downloaded file on disk couldn’t be opened.
NSURLErrorCannotParseResponse
A response to a connection request couldn’t be parsed.
NSURLErrorCannotRemoveFile
A downloaded file couldn’t be removed from disk.
NSURLErrorCannotWriteToFile
A download task couldn’t write the file to disk.
NSURLErrorClientCertificateRejected
A server certificate was rejected.
NSURLErrorClientCertificateRequired
A client certificate was required to authenticate an SSL connection during a connection request.
NSURLErrorDataLengthExceedsMaximum
The length of the resource data exceeded the maximum allowed.
NSURLErrorDataNotAllowed
The cellular network disallowed a connection.
NSURLErrorDNSLookupFailed
The host address couldn’t be found via DNS lookup.
NSURLErrorDownloadDecodingFailedMidStream
A download task failed to decode an encoded file during the download.
NSURLErrorDownloadDecodingFailedToComplete
A download task failed to decode an encoded file after downloading.
NSURLErrorFileDoesNotExist
The specified file doesn’t exist.
NSURLErrorFileIsDirectory
A request for an FTP file resulted in the server responding that the file is not a plain file, but a directory.
NSURLErrorFileOutsideSafeArea
An internal file operation failed.
NSURLErrorHTTPTooManyRedirects
A redirect loop was detected or the threshold for number of allowable redirects was exceeded (currently 16).
NSURLErrorInternationalRoamingOff
The attempted connection required activating a data context while roaming, but international roaming is disabled.
NSURLErrorNetworkConnectionLost
A client or server connection was severed in the middle of an in-progress load.
NSURLErrorNoPermissionsToReadFile
A resource couldn’t be read because of insufficient permissions.
NSURLErrorNotConnectedToInternet
A network resource was requested, but an internet connection has not been established and can’t be established automatically.
NSURLErrorRedirectToNonExistentLocation
A redirect was specified by way of server response code, but the server didn’t accompany this code with a redirect URL.
NSURLErrorRequestBodyStreamExhausted
A body stream was needed but the client did not provide one.
NSURLErrorResourceUnavailable
A requested resource couldn’t be retrieved.
NSURLErrorSecureConnectionFailed
An attempt to establish a secure connection failed for reasons that can’t be expressed more specifically.
NSURLErrorServerCertificateHasBadDate
A server certificate is expired, or is not yet valid.
NSURLErrorServerCertificateHasUnknownRoot
A server certificate wasn’t signed by any root server.
NSURLErrorServerCertificateNotYetValid
A server certificate isn’t valid yet.
NSURLErrorServerCertificateUntrusted
A server certificate was signed by a root server that isn’t trusted.
NSURLErrorTimedOut
An asynchronous operation timed out.
NSURLErrorUnknown
The URL Loading System encountered an error that it can’t interpret.
NSURLErrorUnsupportedURL
A properly formed URL couldn’t be handled by the framework.
NSURLErrorUserAuthenticationRequired
Authentication was required to access a resource.
NSURLErrorUserCancelledAuthentication
An asynchronous request for authentication has been canceled by the user.
NSURLErrorZeroByteResource
A server reported that a URL has a non-zero content length, but terminated the network connection gracefully without sending any data.