Hi WN,

re:
> There is also no control when measuring the radius inside the circle behind the center.

Can you please describe this one a bit more? If you could also post the .3dm model file that may help me understand.

re:
> After fixing the radius dimension line, if the cursor remains in the same place,
> then the extension line with the text is not fixed, only the arrow and the radius line remain on the screen.

Yes this will happen if the 2nd and 3rd points are stacked up on top of each other. You can fix it by selecting the dim, using Edit > Show pts on it, and then dragging the last point so there is some distance between it and the previous point.

- Michael