It works also in SugarCRM CE Version 6.5.22 (Build 1055)
I am having a very similar issue. I've updated all the way to 6.5.22 (from 6.4.x where the issue started). Here's my error:
ERROR CONNECTING to: ./index.php?entryPoint=json_server, ERROR:SyntaxError: JSON Parse error: Expected '}'
I have commented out the line in the utils.php and it doesn't change anything.
Retrieving data ...