Not quite sure if that's what the OP had in mind, but I'm having a problem building the last part of a palisade next to a ridge. Case in point:

I cannot extend the palisade to that empty square next to the rigde; I tried approaching it from distance, different angles, etc. - nothing works. Furhtermore, I cannot place any square-sized object there (e.g. tanning tub, wicker basket), the only thing I can place a signpost for is a dream catcher. Shift-placing also doesn't work - it either intersects the existing palisade and I get an error message, or the signpost simply does not appear. On the other hand, a character can walk through that square without any issues.
Any suggestion how I can plug this hole in my wall?