I am also having trouble with Visual Composer
If I try to edit the main home page with VC I simply get 3 blue yellow green blocks as I wait indefinitely.
When editing a blog post, I have found that VC is not available at all.
It seems you are using wrong plugin.
You have to use WPBakery Page Builder plugin saved in the theme directory gillion/inc/plugins/js_composer.zip
After using the correct plugin if you are still facing the issue then this can be due to plugin conflict on your site so please try temporary deactivating all plugins except Visual Composer plugin and see whether everything works fine and then enable the plugins one by one to see which plugin is conflicting if any.