Attack log:
https://www.torn.com/loader.php?sid=attackLog&ID=0f0474b07e37f856a5e2617b16af5c76
On attempting to Mug, "200 SyntaxError: Unexpected token <" was the error and the page then re-set to the Leave/Mug/Hospitalise screen.
I re-tried four times to Mug, settled to 'leave', which worked as expected.
I had successfully mugged other users previously (post attacking 2.0 update).
Screenshot of error:
http://s3.amazonaws.com/profileimages.torn.com/4e9115d8-c626-850e-748987.png