Screen Recording failed to save after iOS 12.0.1

When I finish screen recording with my iPhone 7 Plus, I get either of these two dialogues (sometimes both, in the very following order):

“Screen Recording failed to save due to:

The operation couldn’t be completed.

(cocoa error -1).”

“Screen Recording failed to save due to:

Failed to save recording.”

I have 140.81 GB free space. I’ve already hard booted my iPhone, and I’ve also Reset All Settings, but it still refuses to save.