When I click on a single post my browser goes to about:blank#blocked and the page is white

Question

I have a single.php template, I also have index.php but it's not reverting to that, its just saying

'about:blank#blocked'

in the address bar and displaying nothing on the page.

I've tried changing echo the_permalink() to just the_permalink(), I've saved my permalink settings to post name. I've also deactivated all plugins. Any ideas?

My archive.php loop is as follows:

if (have_posts()) :
   while (have_posts()) :
    ?>
    <div class="card container mb-3">
        <a href="<?php
            // this conditional outputs the permalink for programmes and events, and an external url to resources
            if (is_post_type_archive( $resources )) {
                echo 'https://' .  get_field('website');
            } else {
                echo the_permalink();
            }
        ?>">
        <div class="card-body row"><?php      
        the_post();

            ?>
            <div class="col-sm img-fluid"><?php 
                the_post_thumbnail('medium');
            ?></div>
            <div class="col-sm p-2 m-0"> 
            <h2 class="card-title text-center"><?php the_title(); ?></h2>
            </a>
            <?php



// This section gets any custom fields and displays them if they exist

    $fields = get_fields();
            if( $fields ): ?>
                <ul>
                    <?php foreach( $fields as $name => $value ): ?>
                    <li><?php
                    echo $value;
                    ?></li>
                    <?php endforeach; ?>
                </ul>
            <?php 
            endif;          
            ?><p class="card-text"><?php the_excerpt(); ?></p>
            </div>
            </div> <!-- card body -->
    </div><!-- card -->
            <?php

    endwhile;
endif;

?>

Thanks

Answer 1

the_post() should be called at the start of the while loop (or The Loop). I.e. Before you call functions like the_permalink() and the_title() which point to the current item in The Loop.

So your while loop should start like so: (and remove the other the_post(); in your code)

while ( have_posts() ) : the_post();

And the browser sent you to about:blank#blocked most likely because the a element had an invalid href (URL) value: https:// as in:

<a href="https://">Example</a>

And it's very likely because the get_field('website') returned an empty value; for example, because of a wrong post data (ID/object).

So this part:

if (is_post_type_archive( $resources )) {
    echo 'https://' .  get_field('website');
}

could be rewritten to this:

if (is_post_type_archive( $resources )) {
    if ( $url = get_field('website') ) {
        echo 'https://' . $url;
    } else {
        the_permalink();
    }
}

But I'm assuming the website field doesn't start with the protocol (e.g. https:// or http://).

And there's no need to echo the_permalink() because the function already echoes the permalink/URL.