I have this code that can\'t send a Facebook request until now.
NSDictionary *firstDict = [NSDictionary dictionaryWithObjectsAndKeys: @\"image\", @\"Type\",
dataUsingEncoding: is a NSString method, so presumably, some object is expecting an instance of NSString where you passed an array. I presume that FBRequest cannot deal with the array you included in the attachment dictionary.
dataUsingEncoding:
NSString
attachment