Curve cannot be bent using command

Rhino Rhino for Windows
1

cannot bend.3dm (2.5 MB)

Hi guys, i have a problem on the simple command of “bend” on rhino. i have a curve that simply cannot be bent. when i create the spine with the bend command, and then proceed to bend it, the original curve simply remains unchanged.

please kindly help me have a look? really appreciate it.

Cheers,
yung to

2

The curve is a polyline with 75651 points. That may be too many points.

3

use the “rebuild” command. reduce the point count to 5000 or less. change degree into 3.
then you should able to use “bend” command.
cannot bend-1.3dm (573.6 KB)