Implementing template tags in Misty Lake

I’m trying to integrate Co-Author Plus’ template tags with the Misty Lake theme per these instructions, but I cannot get co-authors to show up on the front end. I added this code snippet to single.php:

if ( function_exists( 'coauthors_posts_links' ) ) {
    coauthors_posts_links();
} else {
    the_author_posts_link();
}

but no dice. Misty Lake has the function mistylake_posted_on, so I added the snippet:

if ( ! function_exists( 'mistylake_posted_on' ) ) :
/**
 * Integrate Co-Authors Plus with Misty Lake by replacing mistylake_posted_on() with this function
 */
function mistylake_posted_on() {
    if ( function_exists( 'coauthors_posts_links' ) ) :
        printf( __( '<span class="%1$s">Posted on</span> %2$s <span class="meta-sep">by</span> %3$s', 'mistylake' ),
            'meta-prep meta-prep-author',
            sprintf( '<a href="%1$s" title="%2$s" rel="bookmark"><span class="entry-date">%3$s</span></a>',
                get_permalink(),
                esc_attr( get_the_time() ),
                get_the_date()
            ),
            coauthors_posts_links( null, null, null, null, false )
        );
    else:
        printf( __( '<span class="%1$s">Posted on</span> %2$s <span class="meta-sep">by</span> %3$s', 'mistylake' ),
            'meta-prep meta-prep-author',
            sprintf( '<a href="%1$s" title="%2$s" rel="bookmark"><span class="entry-date">%3$s</span></a>',
                get_permalink(),
                esc_attr( get_the_time() ),
                get_the_date()
            ),
            sprintf( '<span class="author vcard"><a class="url fn n" href="%1$s" title="%2$s">%3$s</a></span>',
                get_author_posts_url( get_the_author_meta( 'ID' ) ),
                esc_attr( sprintf( __( 'View all posts by %s', 'mistylake' ), get_the_author() ) ),
                get_the_author()
            )
        );
    endif;
}
endif;

to all the files which call mistylake_posted_on: content-format.php, content-single.php and content.php (these are all the places mistylake_posted_on turned up when I grepped the term in the theme’s directory). Still no dice. Added it to single.php. No dice.

I am flummoxed. Should I be taking a different tack with this? The only other thing I can think of is adding trying to tie it to the conditional is_single(). Anyone have any thoughts?

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