Hi Deepak,
i have pushed the release. Please try upgrading and let me know how it goes.

Please do see this post for upgrade info
https://buddydev.com/support/forums/topic/upgrading-to-mediapress-with-sitewide-wordpress-gallery-support/

Ok,
Here is a slightly modified version of your last function

function list_author_used_terms($author_id){

    // get the author's posts
    $posts = get_posts( array('post_type' => 'post', 'posts_per_page' => -1, 'author' => $author_id) );
    $author_terms = array();
    //loop over the posts and collect the terms
    foreach ($posts as $p) {
        $terms = wp_get_object_terms( $p->ID, 'collection');
        foreach ($terms as $t) {
            $author_terms[$t->term_id] = $t;
        }
    }
    return $author_terms;
}

and here is an example use

$terms = list_author_used_terms( 1 );
$links = array();
foreach( $terms as $term ) {
	$links[] =  sprintf( "<a href='%s'>%s</a>", get_term_link( $term ), $term->name );
}

echo join( '', $links );

Hope that helps.

You have some plugin/rewrite rules causing this issue. If I directly try to access the mediapress image, I see this message

WPPP dynamic images deactivated for this site

Can you please look into that.

Hi Jan,
Just updating that a new update is coming in couple of hours now. That should fix all the bugs.

Hi george,
Can you please point me to your site/activity page?