Openrocket not calculating CP with fin height of .01 but does with fin height of .1

[burkefj]

I was building a model in openrocket for mass balancing primarily, to that end I have a motor mount that is held in by two fin tabs and just a strip in the bottom. In order to model the weight of this I simply made a fin on the bottom with the right tab length and height and made the actual fin heigh .01". All of a sudden my CP calculation said "N/A" and in looking at details on the fins in the info section the CP of this .01 tall fin was NaN.
I changed the fin height to .1 and it came back, is this some sort of weird rounding issue causing a div/0? The component in question is called "Motor Tube Tab"

Here are the two models and two photos, the fin in question as at the rear bottom. Both using the latest version of the software 23.09. Top picture with fin height at .1 showing CP and bottom pic with .01 fin height and N/A. Both Openrocket files attached.

 

[neil_w]

Looks like a degenerate case we are not handling properly. Will file a bug. I don't know why it's blowing up, but I'm pretty sure we never tested with a fin that was all tab and no fin.

 

[burkefj]

Looks like a degenerate case we are not handling properly. Will file a bug. I don't know why it's blowing up, but I'm pretty sure we never tested with a fin that was all tab and no fin.

I have been called a degenerate before so ..

 

[neil_w]

Reproduced it easily on the Simple Model Rocket example. Filed as issue 2474.

https://github.com/openrocket/openrocket/issues/2474