I have tried making the same animation 5 times now, all resulting in ROBLOX Studio stopping working. Since the ROBLOX animation plugin does not autosave animations, I am pretty much screwed if I don’t save after every change I make to the animation. The crashing seems to happen when I drag ArcHandles for the limbs.
From my understanding, Load finds KeyframeSequences inside the dummy you are animating, and lets you load in those. Since studio crashed, the autosave by ROBLOX only contains the dummy, but no KeyframeSequence.
I don’t encounter any issues with the default rigs. Can you attach the place/animation rig so I can take a look? If you have a place/rig and repro steps, then that’s even better!