Recently, we got the bugs with Chrome version 6.1.x We just release the new version to solve that. Please update theme with instruction help.king-theme.com/faq/9-how-to-update-the-theme-3f.html
In case you do not want to update, you just replace the file at /wp-content/themes/[purchased_theme]/assest/js/viewportchecker.js by the one from link https://www.dropbox.com/s/ihl82cvjf4bg0tz/viewportchecker.js?dl=0
[purchased_theme]: the theme name you purchased and the child theme also.
If you are using Vixa, Universe, Always and Highstand themes. Please update the KingComposer to latest version also.
Hope that convenient for your plan.