ned's blog
FAQs re problems entering Doom 3 servers 
I can't join servers, I get the following message(s):

"this server requires punkbuster"
"server uses protocol 1.41"
"Data not in sync with server data"

What do I do?

"this server requires punkbuster"

If you get this message when trying to enter a server this means that the server has Punkbuster enabled but you don't. Punkbuster is an anti-cheat & admin control option for server admins to enable if desired. By default it's disabled. If the server you're entering has it enabled then the client (you) must also have it enabled in order to play.

There are a few ways to enable Punkbuster client-side.
This way is probably the easiest for most people.
-start Doom3 from desktop
-select Multiplayer
-select Find Multiplayer Game
-ensure Punkbuster is Enabled (top left)

next thing to do is turn on Punkbuster in the mods you play eg. nedDOOM3
-from the previous step, select Main Menu
-select Mods
-select each mod and repeat the above procedure

With the nedDOOM3 mod, the interface is altered to a point where you may need to edit a file to enable Punkbuster.

-open your Doom 3 install
default location is C:\Program Files\Doom 3
-open the nedd3_rd folder
-open the DoomConfig.cfg with Notepad
-find the line seta cl_punkbuster "0"
-change 0 to 1
-close and save

my server is displayed in the default Doom3 Find Multiplayer Game option
you only need to enter nedDOOM3 via the Mods option if you need to start a nedDOOM3 LAN game

"server uses protocol 1.41"

If you get this message when trying to enter a server then you require the v1.3.1 patch. This simply means that the server is patched to v1.3.1 and you aren't.
(Doom3 v1.3.1 utilises server protocol 1.41)

Doom3 v1.3.1 patch can be downloaded - here -

it can be installed over ANY Doom3 version

"Data not in sync with server data"

If you get this message then you have custom content installed in your base folder which is conflicting with the modded server you are trying to enter. Remove custom files from your base folder to enter the particular server you are getting this error with.

this has NOTHING to do with a server being set to Pure