Spot healing gives me "not enough pixels" error
I am trying to retouch a photo using the normal Spot Healing brush. No matter what I do, I get the "not enough pixels" error. The files seems to be 100% normal. RGB mode (tried CMYK as well). 8-bit. (Tried 16-bit.) It's 100% opaque except for a normal mask. It's one layer. It's not locked. Things I have tried so far:
- Resetting preferences
- Testing another image (it works fine)
- Saving the image as a TIFF, a PNG and a JPEG (the JPEG works; the TIFF and PNG don't)
- Pasting the image from one file to another.
Because the JPEG works, I assume this has something to do with transparency. But I have never seen this behavior before, and I've used Photoshop for decades. I have the current Creative Cloud version.
Does anyone know what's happening here?
