Perpendicular & nearest won't snap to arc

[gadjet]

One of our users has a drawing in which the osnaps are behaving strangely. When trying to draw a line from off an arc (but not at it's center) to the arc, if the osnap is set to either perpendicular or nearest there are some arcs that Acad will not find the snap, it doesn't even show the snap icon for perp or nearest when you hover near them! All of the arcs are at zero elevation. I opened the drawing on my computer, and I am having the same problem, but only with this drawing. Endpoint and midpoint snaps work fine, but perp and nearest will not work. I have tried with both running osnaps, and with just one osnap set, but can’t get them to work. Is there some setting I am unaware of? All the snaps seem to be fine if I snap to a line rather than an arc.

[Arben.Allaraj]

One of our users has a drawing in which the osnaps are behaving strangely. When trying to draw a line from off an arc (but not at it's center) to the arc, if the osnap is set to either perpendicular or nearest there are some arcs that Acad will not find the snap, it doesn't even show the snap icon for perp or nearest when you hover near them! All of the arcs are at zero elevation. I opened the drawing on my computer, and I am having the same problem, but only with this drawing. Endpoint and midpoint snaps work fine, but perp and nearest will not work. I have tried with both running osnaps, and with just one osnap set, but can’t get them to work. Is there some setting I am unaware of? All the snaps seem to be fine if I snap to a line rather than an arc.

It is good to attach this drawing where can I do something.

[CADDmanVA]

I'll agree with Arben, posting the drawing in question does help.

But...to take a stab at it anyhow...

1. Try doing an AUDIT and RECOVER on the drawing. Perhaps there's an error in it.
2. What happens if you WBLOCK the entire drawing out and insert it into a new, blank drawing?

Give these a whack and let us know, and/or post the drawing.

[Commissar Rod]

Does it work if you use a osnap override for the one you want?

[mmccarter]

Do the arcs have an extrusion relative to the UCS when listed?

It sounds as if its the kind of thing which crops up with arcs on non 0 z values which have been flattened maybe. Flattening them will sometimes leave them seen as 3d entities to AutoCAD even though they sit at 0 z value.