Is it possible to get the logs related to visualize.js in jasperserver.log ?

You may want to enable logging to reveal more in the javascript console 

<script type='text/javascript' src="http://localhost:8080/jasperserver-pro/client/visualize.js?logLevel=debug"></script>

Here's additional information on customizing your script with paramaters like this here...

http://community.jaspersoft.com/wiki/visualizejs-api-notes-and-samples-v56