Why editor is not allowing to enter my custom php code after 4.9 version update in WordPress? And showing this error message: "Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.”"
I don't think you can arbitrarily slap php into the editor in the first place but you can give this a whirl. It appears to still work... https://wordpress.org/plugins/insert-php/ hope that helps, Nigel
Not sure whether you were able fix the issue. But you can try doing the following: Into wp-config.php file search for DISALLOW_FILE_EDIT and you should see a function exactly like this define( 'DISALLOW_FILE_EDIT', true ); just change the status to false from true and if you don't find this function then add this function define( 'DISALLOW_FILE_EDIT', false ); and Save
You need to use some of plugin to use PHP code in an editor or need to be good at filters and hooks to modify the actual functionality of Editor. By default, WordPress Editor will not allow to execute Server Side Scripting by putting in to Editor. To overcome this, you need to filter the editor content.