Squash 3 won't import

Whenever I try to drop an image into the Squash window, I get a black exclamation mark in a triangle on a white background, and the image won’t import. I’ve tried photos, screen snapshots, and nothing imports.

I’m using Squash 3.0 (newest version.)

The app was working fine a few days ago, and today won’t work at all. Very puzzling!!

Anyone see anything like this before?

Never mind. Rebooting the computer fixed it. Weird.