Am having the same issue, but from a new install.
WP 3.5.2
ACF 4.1.8.1
(also have Repeaters 1.0.1 but deactivating makes no difference)
I also have no other plugins activated.
Chrome is picking this up as an “Unexpected token ILLEGAL” input.php: line 10.
Have re-chmod’d all folders to 755 and files to 644: no change.