any idea

[belfastblood]

ive been messing around with gmx my first time,i was doing the tutorail the bunker gmx.
i am stuck i got to clonning the bunker adding texture so on linking co10 co11 co12, co10 and co11 link to my bunker but co12 just wont link
i checked the tutorail cafully to make sure i have not left any thing out but i done what the tutorail said but i keep getting stuck on the last co12
any one any ideas and has anyone any links to blue prints of buildings thnx for any help