hi im having trouble with my navameshes

In the Tamriel Cell there are long thick fluoro lines like grid lines or something when in the navamesh window.
they are connected to other navamesh's

my problem is i cant create a navamesh over them - so the path i have made crosses 1 and i cant create a continuos mesh across the fat green line!

i can make my mesh upto that line, but mot cross it.

i can make a mesh on the othe side of the line and but the two together but i can seem to join them.

and so in the game NPCs just stop once they get to that line









Question - Is there a way to merge across the fat green line?



What am i missing ? the wiki for both skyrim and fallout dont cover this

Help would be much appreciated
thx

Nav mesh cant extend across cell borders. Press B to toggle cell border view. They are the yellow dotted lines.