Help me Please With Natural Selection

[Desp]

Hello, Im not that good with computers so i need your help. I just downloaded the latest version of Natural Selection, When i tryed to join a server it gave a error [CL_dlls/cliend+dll ). I need help fixing it.

 

[Desp]

Help!!!

 

[Desp]

I Think i down Loaded 3.0 B1 DO i need to download bata 4 or 5 or can i just update?