NSStreamEventErrorOccurred is triggered while running the application in iOS 11

Question

I am using the socket programming to connect to the local wifi for the communication . The code works fine in the versions lower than the ios 11 but on ios 11 the NSStreamEventErrorOccurred is triggered. The code is given below:

  - (void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
   // NSLog(@"stream event %lu", (unsigned long)streamEvent);
    switch (streamEvent) {
        case NSStreamEventOpenCompleted:
           // NSLog(@"NSStreamEventOpenCompleted :::: Stream opened and connected");
            break;
        case NSStreamEventHasBytesAvailable:
            // NSLog(@"NSStreamEventHasBytesAvailable :::: Stream opened and connected");
            if (theStream == _inputStream) {
                uint8_t buffer[1024];
                NSInteger len;

                while ([_inputStream hasBytesAvailable])
                {
                    len = [_inputStream read:buffer maxLength:sizeof(buffer)];
                    if (len > 0)
                    {
                        NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];

                        if (nil != output)
                        {
                            NSLog(@"server said: %@", output);
                            [self messageReceived:output];
                        }
                    }
                }
            }
            break;
        case NSStreamEventHasSpaceAvailable:
           // NSLog(@"NSStreamEventHasSpaceAvailable :::: Stream has space available now");
            break;

        case NSStreamEventErrorOccurred:{
           NSError *theError = [theStream streamError];
            NSLog(@"Error Description:%@",theError.localizedDescription);
            [self close];
            if(self.delegate &&[self.delegate respondsToSelector:@selector(socketHandlerItem:failureWithError:forSocketType:)]){
                [self.delegate socketHandlerItem:self failureWithError:[theStream streamError] forSocketType:self.socketType];
            }
             //NSLog(@"NSStreamEventErrorOccurred :::: %@",[theStream streamError].localizedDescription);
        }
            break;

        case NSStreamEventEndEncountered:
            [theStream close];
            [theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            if(self.delegate &&[self.delegate respondsToSelector:@selector(socketHandlerItem:eventStopedWithstatus:forSocketType:)]){
                [self.delegate socketHandlerItem:self eventStopedWithstatus:YES forSocketType:self.socketType];
            }
           // NSLog(@"NSStreamEventEndEncountered :::: close stream Disconnected");
            break;
        default:
           // NSLog(@"Unknown event");
            break;
    }
}

May i know is this the specific problem with iOS 11 and what can be the solution for this. Please do suggest a solution.