Can not make planar curve

Hello, My planar curve tool has usually been very effective for all sorts of flat curve shapes; however, this shape has me stumped. I’ve tried projecting the curve to a flat surface thinking the shape was not perfectly flat, and the result still doesn’t work. I also tried making the shape uniform with no luck making a planar curve. I get no error messages, just a blank, open curve. I have also tried cutting the planar curve out of a flat shape, and the shape does not cut the surface. Any help is appreciated. Thank you.

please attach a simple .3dm file.
and maybe a sketch / screenshot of what you re trying to do.

Thanks for looking into this.

without the file itself that will be impossible to discern.

File attached.
Base_001.3dm (2.9 MB)

That profile curve is actually planar… What is it you are trying to accomplish? Are you wanting to sweep the profile around the rectangle you have in the file?

also what is this? are you talking about the polyline or are you using some plug in?

The curve is planar. I’m trying to create a Planar “Surface” which is called Planar Curves under the Surface dropdown menu. From the same Curve, I am going to extrude this to a thickness of 6mm, but will need Planar “Surfaces” to complete a watertight model of the part. I’m talking about the polyline, and I’m not using a plug in. Also, FYI, I’m using the Mac Evaluation of Rhino if that makes any difference.

Here’s a screenshot of the pulldown menu and the selection I’m trying to make or achieve with the polyline.

The curve is planar, but it is not closed. There is a 0.35 gap between the ends. Fix that and you should be good to go.

Oh my gosh. I knew it would be something I overlooked, and something simple. Thank you so much for pointing out the obvious solution. I hope you have a great day!
Thank you!