Error in point load input: couldn't find the node

Hi, I need to add a uniform pressure along the ring circle, but there is no option for this. Therefore I divided the circle and create a series of vector lines that point to the center of the circle >> and use this series of lines to function as “force”.

However there is an error: couldn’t the find a certain node where load 0 is attached.

In a lower green group, I tried again simply one point and one custom vector direction, same error.

Could anyone please give me some advise what does it mean?
Or better, is there a way to apply uniformed pressure load (instead of a lot of point load) along a circle?

Thank you!

(don’t know how to add attachments here, please refer to the post also here, thanks: https://www.grasshopper3d.com/group/karamba/forum/topics/error-in-point-load-input-couldn-t-find-the-node)