Me and my sister both have a gameboyadvance i have an sp she has the original model and were trying to fight pokemon on a link cable and this link cable is a 4 way link cable but when we try and do it one of us alwayz gets an error message saying:

"you need 2 players connected on a link cable" or something but the other player is able to connect is there anything special you need to do like to both connect? or know of any problem the gba has with 4 way link leads instead of 2way? if you can help id be grateful!

I had a three way and it had one connector that was designated as the 'master' plug. Check for something like that. A single dot on one, two dots on another....just a suggestion.