vertical line on elevation

[SHCanada2]

This vertical black line just showed up even though I have not changed the exterior walls in a couple days

 

 

Any ideas? I see these every once in awhile.

 

and just now while I was looking I noticed the footing line was about the same place

 

so for shts and giggles, I turned off the footing layer in plan view, went back to elevation and it is gone. tried to repeat the behaviour and I cannot.

 

then I was in ortho view and I turned on walls, labels, and then the vertical black lines appeared on the back of the house

 

and now I cannot get them to go away. it looks to be because of the side wall (below seems to match the lines), but why just show up at random?

 

then I start fiddling with the wall intersection tool for the one corner, and then poof both corners vertical lines vanish

 

 

unbelievable. what am I missing here? 

 

 

 

 

[DavidJPotter]

I have never seen any such thing myself other than lines associated with a "auto story pole line" but that should be easily identified as such, sorry.

 

DJP