When running a coupled transielt fluid/thermal analysis, I get the above error message. The problem is quite simple: a cooling flange surrounded by air. I raise the temperature of the cooling flange to 75C, with an ambient temperature of 20C and model the air surrounding it as 3D fluid-elements. I do not use a boundary mesh, since I've had some trouble getting it to mesh correctly. Instead, I'm using an all-tethaedral mesh for the fluid, and thermal bricks (bricks & tetra) for the cooling flange.
Then I get the message
"0x7A: 152962 elements were expected for part ID2, but 1790 were found"
This occurs just after the iterations start. After that, the analysis proceeds, so I guess this is just a warning, but what does it mean? Are the results severely affected? It sounds to me as if most of the elements for the fluid (part 2) part has been removed somehow. It looks fine in the results window, however.
Edit: I also noticed something strange. I can access the results from the first two steps, but nothing beyond that, despite that they have converged. Also, the "automatic time-stepping" button is greyed out.