Dimension not working as I expect

I’ve never had this problem before. When I try to set a dimension, say diameter, I get a crosshair. I select a spot on a circle with the crosshair and then press enter. Nothing appears. I notice that sometimes when I start the dimension command, I don’t get a crosshair; I get a little arrow instead. When it presents the little arrow for selection, then it works right and a dimension appears.
I assume I’m doing something wrong, but don’t know what it is. Something new with Rhino 6? rex

Hello - by this do you mean, the DimDiameter command (Arrow, to pick a circle) and not a linear dimension (Dim - crosshairs to set a point at one end of the dimension then the other) that you are using to mark off a diameter?

-Pascal

Yes, I mean the dimdiameter command. Funny thing is that it’s working the way I expect now. I was picking diameter from the dimension menu and it wasn’t giving me an arrow; it was giving me a crosshair. Then when I clicked a point on the circle… nothing. Works now, so I don’t know what was going on.