Cant play campaign in Assassin's Creed Brotherhood and Stuck in Multiplayer mode

I want to play Multiplayer mode in Assassin's Creed Brotherhood. I had at the start got success to play in the single player mode. But when I run the same in multiplayer mode the game freezes. What happens here that when I click on to join the multiplayer game mode the game hangs in between and there is no respond at all. I had to end up the game via Task Manager. My friends plays a well on the game and they do not face the same issue which I am dealing with. Till yet I did not find any solution for the same. What can be done here for this.

This also happens sometime on my system also. Right now I have a Xbox console. The game was downloaded well without any issue. I had played a number of levels in the single player mode and there was not issue at all. But when I tried to join online the game freezes. I think you will need to look for a patch download. See the below link. This patch is designed to fix the most of the issue dealing with online gameplay. Just download the same and then run it. The patch is easy to install and configure. Also check your Internet connection. There must not be fluctuation in the net speed.
Assassin's Creed: Brotherhood Patch 1.01

Assassin's Creed: Brotherhood Da Vinci Disappearance is an high end graphic game. So for that you need an powerful system with high speed Internet connection to play online. I found my friends facing lagging issue in the game while playing online. And as I have a 1 mbps of Internet speed nothing happens in my system. So for this just have a look that when you are online you do not use any downloading application or any application that eats the Internet bandwidth. If you are playing the same on Xbox 360 then try to reboot your Xbox for the few starting errors.

There was a similar issue in my brothers Xbox. He had purchased the game cd of n Assassin's Creed Brotherhood Da Vinci Disappearance. The disc work quiet a well when I play the same on co-operating mode or single player mode. But when he tries to join a multiplayer game the game freezes. He tried a number of times to fix the same but nothing happens there. In the end he ask for the a new cd in replacement and then new disc worked well. So the issue was with the game disc which he was using before. Same can be condition with your system also. Try a re-installation of the game.

For the time being there are some basic tricks that you try to fix the game issue. But later on you will need to get a replace of the game which you had bought if still nothing works there. First you will need to disable certain cpu cores. This is for those you are using multi-core cpu. Set a single cpu to control the game via task manager. You can do that by this. First run the game and then press Ctrl + Alt + Del. In the process menu right click on the game file and choose cpu affinity. Then remove tick from multiple cpu and set it to single only.

Disable most of the startup services from msconfig. This is can be either due to your security application which is blocking the game connection. It happened to me due to Symantec which blocks my game. I play CS which is a old game and it is a pirated copy. Every time when I create server or when I join any it blocks the incoming and outgoing connection terminating my game. You can at the time of gameplay disable your security software and then try back the same.