Forum Moderators: phranque
It is not a real error, it looks like it was caused by an error between the tool you were using and the settings of your site or host.
<a href="<?php echo site_url();?>"
<a href="<?php echo site_url();?> is not complete as posted, it needs a closing html bracket to function, a "> to complete the html of the link. It is not visible on a rendered page, not visible to visitors because it is replaced when the page is viewed, by the URL of your site if the html is complete. PHP is processed server-side so it is only visible to you in your template (usually a text file). When a page is rendered in a browser, the PHP code is not visible to visitors. If it is visible, there is an error in your code. Typically, there is an anchor image or text after the URL so the complete code should be something like <a href="<?php echo site_url();?>"> <img="/logo.png" alt="Home"></a> that goes with the php echo code string. <a href="<?php echo site_url();?> with <a href="https://example.com"> using your homepage URL if you want to remove it - but if it works as expected for you, no reason to change it. If it does what it is supposed to do, then it is not an error, it is an anomaly in the tool you are using.