I uploaded the latest version to two different test sites and have the same issue on both.
I don't use the WYSIWYG but tried with that and it still didn't work.
Anyway the lightbox pops up, I can choose an image but then the popup box goes blank and if I close it the image doesn't appear in the post box. No image, no url nothing at all.
I tried deactivating all plugins and still no go.
ETA: I also can't upload. Have tried re.htaccess resolutions posted in another thread but none of them met with success.