I looked all over the internet and found no answer.
Basically my problem is whenever I try to edit orders and change stores I get the SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data OK in firefox and in chrome I get SyntaxError: Unexpected end of input OK.
Has anyone found a "real" solution for this because I tried all that was suggested but they don't work. From changing the api_id to making a secondary API. And even the .htaccess method.
I got the same error and found away to fix it:
You'll be able to edit the order status now!