Image upload error using Catch Kathmandu 3.9.1

Hello,
Like a few other people, when I try to upload an image to the media gallery the response that an error has occurred, and to try again later. If I try via the “insert – image” file, the boxes are empty and I can’t upload either.

Despite the error message, the image DOES upload to the media gallery but if I try to insert into the post / page, nothing shows. There is also no possibility of choosing the size of the image.

From there on, the screen can often freeze / pixellate and I have to restart the computer.
I have a couple of wordpress.org sites, and the others are working fine using 3.9.1.

After reading some of the forums, I’ve deactivated ALL my plug-ins, and cleared my browser cache but the problem persists.

I’d appreciate some advice here please. The website in question is http://www.dating.stories.com.au

Many thanks