Strange dimensioning problem

[Exar Kun]

I am having an issue with applying dimensions to some walls in one of my projects. I keep getting the "Can't create dimension. Highlighted references are not parallel to first selection." error yet I know these walls are, in fact, parallel.

In the image attached, the wall to the bottom right works fine, as you can see by the dimension going from grid line to wall face. However, the wall in the top left (which I have aligned with the lower right - repeatedly), always gets this error when I try to dimension it. I am having the same problem with the parallel curtain walls of the stair. I can trace a reference plane directly over the top of the wall that supposedly isn't parallel and them dimension to that and it works fine.

Can anyone tell me what's going on?

edit - scratch that. I can't trace a line and have it work but I can draw one that looks the same but obviously isn't...

[Mr Spot]

ahh, aligning doesn't always work. I've experienced walls that refuse to align. Is it feasible to delete it a copy the opposite wall over...? or you'll have to drag the end point so its snaps parallel to the other wall or rotate it to snap

[Exar Kun]

Ok, I'll try deleting it and redrawing. It's just odd. The there must be a 0.000001 degree angle difference between these walls if any as it's in no way visible and using the tape measure on various points along the wall doesn't come up with any discrepancies.

[Mr Spot]

One way to check would be to offset the other wall with a detail line to the appropriate dimension, make sure your in thin lines mode, then zoom right in, i'm sure you'll find a difference.

[Exar Kun]

Thanks - fixed! It had snapped to something I didn't want it to (which was, of course, very, very close to thing I did want it to snap to).

Will have to be a little more careful in future. Frustrating that align doesn't seem to work sometimes though.