How to fix Multiplayer Issues

[MO]

Can't use Multiplayer Setup Dialog

Can't use Multiplayer Setup screen. Can't select roles for a mission, can't vote for a mission, and hitting OK will not do anything.

Solution

This issue can usually be traced to nVidia's nForce networking controller. The solution is to use a different network card, if available.


Work around to be traced back

Enable native XP2 firewall, or, if using 3rd party firewall, enable Arma and uPnP architecture.


Can't find servers

No servers show up in the serverslist.

Solution

Open the file hosts in the directory "C:\WINDOWS\system32\drivers\etc" and delete all entries except "127.0.0.1 localhost".

Solution

Ensure that applications such as PeerGuardian are not blocking GameSpy.

Can't connect on servers

Every attempt to connect to a server fails with an error message saying that the attempt to connect failed.

Solution
Execute

netsh winsock reset netsh winsock reset

with cmd. ( CMD is dos command panel, type CMD in windows search and find it ) and then restart windows.

If it still does not work, make copy of your registry and do the following:

Start Windows in safe mode, go to device manager, show hidden devices and delete the following non-PnP-drivers:

HTTP
AVMPORT
NetBios over TCP/IP
TCP-IP
Driver for automatic RAS-connection
Windows Socket 2.0 Non-IFS

"Bad Version" when joining multi player server

When trying to access our Clan's server, I get a message saying "Bad connection, connection refused by server".

The "Bad Version" message will be shown when the server has equalModRequired active and you try to contact with a different set of modfolders.

"You cannot play/edit this mission it is dependent on downloadable content that has been deleted CAA10"

The tool BIS released that removes the old Beta (1.07 et. al) folders, accidentally have deleted the A-10 addon (which is what the missions in questions require)

Unfortunately the only solution is to reinstall.

Arma crashes when connecting to servers

Any attempt to connect to a server crashes ArmA with an error message "arma has encountered a problem and needs to close"

Solution

Solve it by deleting some troublesome MP cache files ~

C:\Documents and Settings\user profile\local settings\application data\ArmA

Delete the ArmA folder, and try to connect to some servers.

"Receiving Mission File" dialog hangs while no mission downloads

When joining a multiplayer game, you can view and join servers but upon connection, the MP dialog hangs at "Receiving Mission File (0kb / 0kb)". This dialog will not move or update.

Example: img405.imageshack.us/img405/3154/armaerroroe6.jpg

Solution

Your software or hardware firewall is blocking the ports ArmA uses to update your game files. Try disconnecting your router and plugging your cable/dsl modem directly into your PC. (Be sure to start Windows Firewall to continue protection if you do this) If you have a software firewall, make sure that ArmA is "Enabled" or "Unblocked" in your profiles of accepted connections.

If you find that it's your router blocking the ports, you'll need to open UDP ports 2302-2305 for the game to function with a router.