Have you recently installed a new wordpress theme and encountered “Call to undefined function wp_body_open()” error or see an empty white screen? Here are the steps you can follow to check and mitigate the error.
Do a View Source of your home page and check the html output. Make sure you caches are cleared from CDN or server.
If you find that there is no code after the <body> tag start in the html source code then this is the problem we are going to address. If you can see the entire content as it should be then this solution is not for you.
Check your error log or activate wordpress debug mode to display the PHP errors and warnings. You can also add a few lines of code to your htaccess file to get the same results. To learn more about activating debug mode refer to this article here. I use the easy method of viewing the error log file in my blog’s root folder using my webhosting’s file manager.
Do you see something like – Call to undefined function wp_body_open()? This means your new theme is looking for a specific functions that your wordpress cannot provide. This happens mostly with older wordpress versions.
Upgrade to the latest wordpress version. If you PHP version is lower than 5.6 it won’t let your install the latest wordpress update. So your next step is to upgrade PHP version. If your hosting provider gives you the MultiPHP tool in the cpanel you can easily choose a higher version of PHP for your selected domain. But, If that feature is not available then you will need to seek the hosting providers tech support help to get the right PHP version installed for your site.
That should sort out the Call to undefined function wp_body_open() problem or empty white screen problem in wordpress.