Why can't you write programs like this? Do you understand?

Because there must be enough source features to create the plane from (least 3).
PNT1[1..12] is one input feature. Split it up: PNT1[1], PNT1[2], PNT1[3..PNT1.NUMHITS]

I don't think it worked

Try .NUMHITS instead of V_COUNT, see if that works

Try .NUMHITS instead of V_COUNT, see if that works

I think the effect is the same, it's the numerical value

WilliamL, I understand what you're trying to express, but I feel like it's a problem with this software version

Now that you have tried everything, I agree. This may be a bug. You may try what I said above, do PNT1[1]..PNT1[12] Or just do each point 1 at a time.

With loops, if you do a construction and select a point, does it show each instance of the point in the window?

     I tried it without any problems in the 2017 version

It will be painful, but try 

CONSTR/PLANE,BF,PNT1[1], PNT1[2], PNT1[3], PNT1[4], PNT1[5], PNT1[6], PNT1[7], PNT1[8], PNT1[9],PNT1[10], PNT1[11], PNT1[12]

To see if it will even work at all.

Brother, of course that's possible

What if you did this? Sorry I keep asking you to test things, I don't have a way to test this.

PNT1[PNT1[1]..PNT1[12]]

Cool, very nice

Brother, I must give you a thumbs up

 Neil Challinor or Don Ruggieri 

Was there a change to how loops work in 2024.1? In Henniger's example, he is using 2023.2 and can construct the plane like this

CONSTR/PLANE,BF,PNT1[1..V_COUNT],,

But for yunyan, he had to do it like this in 2024.1, as the other methods suggested to him by users here did not work. He also tested it in his own 2017, and the previous method worked, you can see screenshots above.

CONSTR/PLANE,BF,PNT1[PNT1[1]..PNT1[V_COUNT]],,

Are we doing something wrong? Or is this the new way?