This is with the current latest release v0.2.2 on macOS 11.2.1 (if that's relevant):

If I try to export a sprite sheet, then modify it in an external program, then import it, I get a "could not load" error message. It also doesn't seem to matter whether I modify it externally, since export sprites.png and then import sprites.png shows the same error. Nothing seems to be logged to stdout or stderr.

Same issue for me

Note that this seems to be workaround-able by dragging the new sprites.png file into the sprite editor while sprite 0 is selected.

Okay. i have mac as well. And issue is the same. I get a "could not load" error message. I have worktime(employee monitoring) software installed on my mac because it is work laptop. So is there a solution?