Tried that. Set the allocation back to 500G. Error went away. When I bumped it back up to 800G, the over-allocation error comes back.

Tried that. No effect.

I recently replaced my hard drive via cloning. Blue Iris 4 is now upset because it believes that the C: is over full. Get a red "!! C: -253.9G" alert at the bottom. How do I tell it that there is now plenty of storage available?