Sorry, that file cannot be edited in WordPRESS

The message “Sorry, that file cannot be edited.” in WordPress usually appears when you’re trying to edit a file (like theme-editor.php) through the WordPress dashboard, but it is restricted or unavailable for editing. Here are some possible reasons and solutions:

1. File Permissions: The file permissions may be set to restrict editing. If the file permissions are too strict, WordPress will not allow you to make changes.
2. Security Plugins: Security plugins may block access to sensitive files to prevent unauthorized changes. Plugins like Wordfence or Sucuri often enforce such restrictions.
3. Hosting Restrictions: Some hosting providers restrict file editing through the WordPress dashboard for security reasons. They may require you to use FTP or the file manager in your hosting control panel instead.
4. Code in wp-config.php: There may be a line of code in your wp-config.php file that disables the theme editor in WordPress. Look for this line: [Code 1.0.1]
5. WordPress Multisite: If you’re running a multisite installation, the network administrator might have disabled file editing for network security.
6. Code in function.php: There may be a line of code in your function.php file that disables the theme editor in WordPress. Look for this line: [Code 20.1]

//Code 1.0.1
define('DISALLOW_FILE_EDIT', true);

//Code 2.0.1
$file = wp_normalize_path( $file );

Solutions

1. Check File Permissions:
   • Use FTP or your hosting control panel to access your WordPress files.
   • Ensure that the file has the correct permissions (usually 644 for files and 755 for directories).
2. Disable Security Plugins:
   • Temporarily deactivate any security plugins and try editing the file again. If this works, you may need to adjust the plugin settings.
3. Modify wp-config.php:
   • Access your site via FTP or your hosting file manager.
   • Open the wp-config.php file.
   • Look for the DISALLOW_FILE_EDIT constant and ensure it is set to false or remove it altogether (Code 1.0.2).
4. Contact Hosting Provider: If your host is blocking the file editing, reach out to their support team and ask them to enable it or provide an alternative method.
5. Modify function.php:
   • Access your site via FTP or your hosting file manager.
   • Open the \wp-includes\functions.php file.
   • Look for the function validate_file( … ) and comment out the normalize in this function (Code 2.0.2)..
   • The function converts the backslash \ in $file to a forward slash /, which causes it to fail the $allowed_files check. See the example in Ref: 2.0.2

//Code 1.0.2
define('DISALLOW_FILE_EDIT', false);

//Code 2.0.2
// Normalize path for Windows servers
// $file = wp_normalize_path( $file );

Ref 2.0.2

For example:

• Original $file: C:\xampp\htdocs\wordpress/wp-content/themes/your-theme/style.css
• After applying wp_normalize_path: C:/xampp/htdocs/wordpress/wp-content/themes/your-theme/style.css

Meanwhile, $allowed_files = ['style.css'] still points to C:\xampp\htdocs\wordpress/wp-content/themes/your-theme/style.css.