Maybe try to redraw it again so that when you try to link, it highlights the spot you link it to. I.e. if you use ADE ???
Possibly a tiny little bit more information may be needed to tell us what we can do to help you?
You mean the yellow taxiway center line? The others look to me like they are ground poly?
You do have a runway black center line, don't you? Just connect the taxiway link to the runway center line and if you do not want to have it show up, then use a taxipath (green).
Unless you mean the taxiway edge line? In that case just put a blue node at the edge of the runway and the taxiway edge line will go not further on to the runway.
Sorry, bed time for me.