Elementor shows an error when it cannot locate the .htaccess file. The error stops the preview from loading. The missing file prevents Apache rewrite rules from being applied. Without those rules WordPress permalinks break and Elementor preview iframe fails.
The issue usually appears after a fresh install, migration, or when permissions block access. It also occurs if the server disables AllowOverride or SELinux hides the file. The error message includes the full path to the expected .htaccess location.