FBError
This class is no longer available in the most recent version of the SDK.
A more recent version of this class is available. Check out the latest version.
Constants
FBErrorInnerErrorKey
extern NSString *const FBErrorInnerErrorKey;
Discussion:

The key in the userInfo NSDictionary of NSError where you can find the inner NSError (if any).

Declared In: FBError.h
FBInvalidOperationException
extern NSString *const FBInvalidOperationException;
Discussion:

This exception is raised by methods in the Facebook SDK to indicate that an attempted operation is invalid

Declared In: FBError.h
Typedefs
FBErrorCode

Error codes returned by the Facebook SDK in NSError.

typedef enum FBErrorCode {
FBErrorInvalid = 0,
FBErrorOperationCancelled,
FBErrorLoginFailedOrCancelled,
FBErrorRequestConnectionApi,
FBErrorProtocolMismatch,
FBErrorHTTPError,
FBErrorNonTextMimeTypeReturned,
} FBErrorCode;
ConstantDescription
FBErrorInvalid

Like nil for FBErrorCode values, represents an error code that has not been initialized yet.

FBErrorProtocolMismatch

The operation failed because the server returned an unexpected response. You can get this error if you are not using the most recent SDK, or if you set your application's migration settings incorrectly for the version of the SDK you are using.

If this occurs on the current SDK with proper app migration settings, you may need to try changing to one request per batch.

Discussion:

These are valid only in the scope of FacebookSDKDomain.

Declared In: FBError.h