Image Upload Trouble

Somehow I think I broke WordPress. In uploading an image to add to an old blog post, something’s going terribly wrong.

I’m able to upload the image, but in my Media Library it displays as a gray square. If I click Edit Image, the image is there and looks fine. But if I insert it into a post, nothing displays. I can see the image code in the HTML but there’s no sign of the image in either the visual Editor or via Preview Changes.

Suspecting a corrupt image, I uploaded another. Same problem. Then I resized an image in Photoshop Elements and uploaded that. I see the same symptoms. I seem to be unable to upload and use any images all of a sudden.

I uploaded an image just 2-3 days ago without incident and I haven’t added any new plugins or done anything that should have changed how WordPress works.

Any ideas?