Most probably It might happen after you upgrade your WordPress version. Because some themes still not supporting to the Last version of Gutenberg editor plugin, the most easiest way to overcome this issue is to switch the default editor with the WordPress Classic Editor plugin.
Mortify the theme support;
add_theme_support( ‘post-formats’, array( ‘aside’ ) );
add_post_type_support( ‘post’, ‘post-formats’ );
Many of you may have experienced this issue after updating your WordPress version (specially after WordPress 5.6). The conflict caused by WordPress 5.6 updated Gutenberg editor with your excising theme’s visual editor. Keep in mind that this is not the issue called White Screen of Death (WSoD).
There are 2 suggestion to overcome this issue by the WordPress Community.
I got this error when I try to do update using Elementor page builder on Consulting – Business, Finance WordPress Theme . First I thought It is some error with theme or any plugin associate with the theme. But the actual reason is the function block by the server’s security feature.
This is how I solved it
Click & Go to ModSecurity
Look for user exact domain and select Off. (For all domains, ModSecurity is On by default)
If you get this message without loading your WordPress site it means the PHP code in your site is not compatible with the version of PHP your site is currently using. More specifically, the issue is with the outdated MySQL extension which was removed as of PHP 7.0.
If you’re using any version of PHP above 7.0 and you’re seeing this error, it’s due to old code that needs to be updated.
Solution 1 : If you unable to upgrade your WordPress installation to the latest for some reasons (i.e. – plugin compatibility) you have to downgrade the server PHP version. (v 5.6)
In order to do it please follow the instructions given by your hosting provider.
If you use cPanel, Read – Switching PHP Version within cPanel
Note: We are not recommending this as a permanent solution. Making changes to your PHP version may impact your site. We encourage you to verify that your site is functioning properly after making any changes.
Solution 2 : You will need to upgrade the core WordPress files to the current version, as well as any plugins your site is using.
When you try to edit TXT record in DNS Zone editor in cPanel, you might getting following error saying,
“You must specify a valid zone name.”
As a solution you can type the ‘domain name‘ instead of typing ‘@‘.