i am making a small map (learning the basics) and i have followed a youtube guys video,and tryed to compile my map,and then the following error appears while loading the map and on the launcher console,hope u guys can help me.

ERROR: Pathnode (End) at (-273.8 66.8 -16.125) has no connections leaving it.

Thank you

It seems for me that you have a window or something and you didn't put pathnodes near it.

How can i add them?

Copy those co ordinates in the error . Open radiant and go to misc find position and it will take you to the exact place the error is. No connections leaving it is likely it is not connected to another node.

In game type developer 1 into console then ai_shownodes 1 to get a view in game.  Blue lines are connected paths red x is disconnected.  The red lines are the drop traverses if you have any .