Make an animal twice as long and you make it eight times as heavy — mass grows with the cube of length. But a bone’s strength depends on its cross-section, which grows only with the square. So weight outruns bone, and stress climbs with size. This is the square-cube law.
That is why giants can’t just be scaled-up versions of small animals. To stay under the failure line they need disproportionately thick, straight, column-like limbs — graviportal posture, like an elephant’s, not a gazelle’s.
Sauropods cheated the weight side too. Their vertebrae and limb bones were pneumatic — hollowed by air sacs — shaving mass without losing much strength, which let them grow larger than any land animal since.
There is still a ceiling. A bone must also carry its own weight, and a column’s self-stress is set by its height no matter how thick you make it — so beyond a point, no amount of extra bone can save you.
Something in the simulation stopped unexpectedly — the lesson continues without it. Nothing you did was wrong; you can move on.