[Theme: gamesdir] printf: too few arguments in template.php

My website is using the Flexithemes Gamesdir theme. I’m attempting to build a game and tech-related news and review site. Instead of showing an image in the slider, however, I only receive the error:

” printf(): Too few arguments in template.php on line 16″, which would be the printf line in the snippet below:

<?php if($this->theme->display('thumbnail', $featuredposts_moreoptions)) {
                            if($slider['link'] && $slider['img']) {
                                printf("%s<img src=\"$slider[img]\" />%s", "<a href=\"$slider[link]\" title=\"$slider[title]\">", "</a>");
                            } else {
                                echo "<img src=\"$slider[img]\" />";
                            }
                        } ?>

I have no PHP experience and can’t make heads or tails of this. I tried reading through the printf documentation but don’t understand what should be happening or what arguments are misused. Would love a bit of help. Thank you.