Structure newbie. Using Revit Structure module within Revit. Not Robot. It has an extension called Analysis > Static Analysis of Frames. I have a simple bent A-Frame consisting (entirely) of two beams intersecting at the peak of the "A." I applied fixed boundary conditions (after trying all other combinations) to the (3) nodes. When I send it to the extension, all seems fine, but when I hit "Calculations" I get the "unstable structure" bit. It does still run the calculations...
Note: There's also an extension called Analysis > Static Analysis of Beams, with which I've had no problems.
File uploader not letting me for some reason, but it's as simple as described above.
Thx,