Maybe because you're creating multiple bodies. I believe that is not supported.
You can however then make the profile longer on that end, then do the Normal Cutout, and then again make it shorter again.
Is the 6in large enough to pass completely through both flanges?
I've gone up to 20in, "Thru all", and nothing makes it happy. Might be time for GTAC.
*edit* Also, I tried doing this one first, thinking maybe it didn't like being the second Normal Cutout, but no luck.
I managed to get the hole on the Flange but not on the Tab. I moved LinkedBody(6) little bit lower. I guess that the problem was with the position of the tube/curve. It was looking just a little bit over the bend.
But funny thing is, that if I try to create new Normal cutout somewhere in the middle of the model (no tangency to anything, no multiple bodies, etc.) I get the same error as you do.
I found this on GTAC Solutions:
The problem where the "Normal Cutout" was not working on a particular part for no discernible reason has been investigated and the following has been found. A workaround exists for the situation. Move the solid body to the Work layer (layer 20 in the case of the supplied part) and then apply the "Normal Cutout."
So, click on Menu/Format/Layer Seetings and make layer 1 work layer.
I tried and it works.
It's a known problem with Normal Cutout.
Dave, make layer 1 your work layer - the cutout should work.
wth? lol, yeah, it works, but I wouldn't have guessed that as the work around.
Thanks again Ben!