Every Time I host a game my friend gets this error:

Error: the game session is no longer available

And vice versa

I host the game by going on Host Online Then
I change the session to nazi zombies
I rename the game
I leave the other options default and I press ok
I then invite my friend and he get the aforementioned error and vice versa.

We both use the disc version of W@W

All help is appreciated Thank You

I am having the same problem! I even used the LAN fixed exe and the tungle LAN client and still I get the same error as OP
there must be something we are doing wrong, does anyone know a solution?

this happened to me i disabled my firewall and so did my friend and it worked fine after that, give that a bash and see if it helps

Thank for the reply, I turned off my firewall and told my friend to turn off the firewall and I try to join his game but still the same error 

Error: the game session is no longer available

This starting to get annoying Help!?!? please

I am having the same problem... 

I have finally found the solution to this problem!
Steps to get Error: the game session is no longer available Fixed
This method is called Port Forwarding and it is used to open a port so that your router firewall does not block world at war

• Find your IP address, then copy and paste it into your internet browser URL
• A page with your Internet service provider will come up and will ask for username and password which can be found on the bottom of your router
• Once you logged in, go to advanced then security then port forwarding and add a new port. (this bit will vary for everyone depending on your provider but its the same sort of thing though)
• Name it anything like COD5-1 - Type should be TCP & UDP - Start and finish port should be 3074
• Save it then Make another new port Name: COD5-2 - Type: TCP & UDP - Start and Finish port: 28960 (If it asks for an IP put the IP your gaming pc is using)
• Save It and you should be done!!!

Videos that might help if you are still confused
http://www.youtube.com/watch?v=rt4qkaLQjJg
http://www.youtube.com/watch?v=qmaR18MOC7c

Go on world at war and enjoy!
I thought I would write the solution to help someone cause the thread on ZM from years ago still has not got a proper solution! No need for lan fix or that add spamming bullsh*t tunngle
Hope this Helps!!!
Just in time for ORIBIT

This worked perfectly! Thanks for posting the solution, I saw port forwarding on YouTube but didn't think that would solve it but apparently it does.