Manual updating themes and plugins is recommended only if auto updates aren't possible then you do the above. In chrome you can clear your cache by going to chrome://settings/cookies enter in the search bar and click remove all clearing all locally stored data for your website. One more thing to do is clear your cache for your website. Some themes may offer support and do the ftp uploading for you if you provide them with ftp username password. These 3 steps are a little nerve racking if you are not familiar with uploading files directly to your public_html root directory of your website. I had to manually comment out the trouble code to get the errors to go away.

This got vc working again but left me with some weird errors happening in vc_templates vc_column.php file.

At this point you should be able to update visual composer from the wp dashboard if it hasn't already. This is updated in plugins outside the theme.

Uploaded latest version of js_composer which was bundled with the theme. I updated js_composer the same way as step 1.I renamed the theme example x-updating once uploaded named the current theme x-previous then changed x-updating to x and deleted x-previous.I downloaded the latest version of the theme because automatic updates were not working. If this is still a problem for you I solved this same error I was getting by manually updating my theme through ftp. I haven't tried this myself just a suggestion. This is where you can find older versions of wp to install This article suggests rolling back your worpress version prior to 4.5.

Visual composer download version 4.11