Use wp_get_theme() to get the theme name on activation

inc/activation.php

@@ -69,7 +69,14 @@ function roots_theme_activation_options_render_page() { ?>
 
   <div class="wrap">
     <?php screen_icon(); ?>
-    <h2><?php printf(__('%s Theme Activation', 'roots'), get_current_theme()); ?></h2>
+    <?php
+    if (get_bloginfo('version') <= 3.4) {
+      $theme_name = wp_get_theme();
+    } else {
+      $theme_name = get_current_theme();
+    }
+    ?>
+    <h2><?php printf(__('%s Theme Activation', 'roots'), $theme_name ); ?></h2>
     <?php settings_errors(); ?>
 
     <form method="post" action="options.php">