diff --git a/lang/en/game.php b/lang/en/game.php
index 1f9db0f..314feed 100644
--- a/lang/en/game.php
+++ b/lang/en/game.php
@@ -230,6 +230,7 @@ $string[ 'convertfrom'] = '-';
 $string[ 'convertto'] = '-';
 $string[ 'gradeaverage'] = 'Average grade';
 $string[ 'gradehighest'] = 'Highest grade';
+$string[ 'common_problems'] = 'Common problems';
 
 // File mod_form.php.
 $string[ 'bookquiz_layout'] = 'Layout';
diff --git a/locallib.php b/locallib.php
index 9581374..f1b3791 100644
--- a/locallib.php
+++ b/locallib.php
@@ -2567,3 +2567,110 @@ function game_use_events() {
 function game_feedback_for_grade($grade, $gameid) {
     return '';
 }
+
+/**
+ * Checks for common problems
+ *
+ * @param stdClass $context
+ * @param stdClass $game
+ */
+function game_check_common_problems($context, $game) {
+    if (!has_capability('mod/game:viewreports', $context)) {
+        return '';
+    }
+
+    $warnings = array();
+
+    switch( $game->gamekind) {
+        case 'millionaire':
+            game_check_common_problems_multichoice( $game, $warnings);
+            break;
+        case 'hangman':
+        case 'cross':
+        case 'cryptex':
+            game_check_common_problems_shortanswer( $game, $warnings);
+            break;
+    }
+
+    if( count( $warnings) == 0) {
+        return '';
+    }
+
+
+    $s = '<ul>'.get_string( 'common_problems', 'game');
+    foreach( $warnings as $line) {
+        $s .= '<li>'.$line.'</li>';
+    }
+    return $s.'</ul>';
+}
+
+/**
+ * Checks for common problems on multichoice answers
+ *
+ * @param stdClass $game
+ * @param string $warnings
+ */
+function game_check_common_problems_multichoice($game, &$warnings) {
+
+    global $CFG, $DB;
+
+    if ($game->questioncategoryid == 0) {
+        $warnings[] = get_string( 'must_select_questioncategory', 'game');
+        return;
+    }
+
+    // Include subcategories.
+    $select = 'category='.$game->questioncategoryid;
+    if ($game->subcategories) {
+        $cats = question_categorylist( $game->questioncategoryid);
+        if (count( $cats)) {
+            $select = 'q.category in ('.implode(',', $cats).')';
+        }
+    }
+
+    if (game_get_moodle_version() < '02.06') {
+        $table = "{$CFG->prefix}question q, {$CFG->prefix}question_multichoice qmo";
+        $select .= " AND qtype='multichoice' AND qmo.single <> 1 AND qmo.question=q.id";
+    } else {
+         $table = "{$CFG->prefix}question q, {$CFG->prefix}qtype_multichoice_options qmo";
+        $select .= " AND qtype='multichoice' AND qmo.single <> 1 AND qmo.questionid=q.id";
+    }
+
+    $sql = "SELECT COUNT(*) as c FROM $table WHERE $select";
+    $rec = $DB->get_record_sql( $sql);
+    if ($rec->c != 0) {
+        $warnings[] = get_string( 'millionaire_also_multichoice', 'game').': '.$rec->c;
+    }
+}
+
+/**
+ * Checks for common problems on short answers
+ *
+ * @param stdClass $game
+ * @param string $warnings
+ */
+function game_check_common_problems_shortanswer($game, &$warnings) {
+
+    global $CFG, $DB;
+
+    if ($game->sourcemodule == 'question') {
+        if ($game->questioncategoryid == 0) {
+            $warnings[] = get_string( 'must_select_questioncategory', 'game');
+            return;
+        }
+
+        // Include subcategories.
+        $select = 'category='.$game->questioncategoryid;
+        if ($game->subcategories) {
+            $cats = question_categorylist( $game->questioncategoryid);
+            if (count( $cats)) {
+                $select = 'q.category in ('.implode(',', $cats).')';
+            }
+        }
+
+        $table = '{question} q';
+        $select .= " AND q.qtype = 'shortanswer'";
+
+        $sql = "SELECT COUNT(*) as c FROM $table WHERE $select";
+    }
+}
diff --git a/showanswers.php b/showanswers.php
index d2ab2d4..9d38566 100644
--- a/showanswers.php
+++ b/showanswers.php
@@ -52,9 +52,9 @@ echo '<br><br>';
 
 $existsbook = ($DB->get_record( 'modules', array( 'name' => 'book'), 'id,id'));
 game_showanswers( $game, $existsbook, $context);
-if ($game->gamekind == 'millionaire') {
-    game_showanswers_extra_millionaire( $game);
-}
+$s = game_check_common_problems( $context, $game);
+if ($s != '')
+    echo '<hr>'.$s;
 
 echo $OUTPUT->footer();
 
diff --git a/version.php b/version.php
index f586f86..9642730 100644
--- a/version.php
+++ b/version.php
@@ -35,12 +35,12 @@ if (!isset( $plugin)) {
 }
 
 $plugin->component = 'mod_game';  // Full name of the plugin (used for diagnostics).
-$plugin->version   = 2017063002;  // The current module version (Date: YYYYMMDDXX).
+$plugin->version   = 2017070201;  // The current module version (Date: YYYYMMDDXX).
 $plugin->requires  = 2010112400;  // Requires Moodle 2.0.
 $plugin->cron      = 0;           // Period for cron to check this module (secs).
-$plugin->release   = '2017-06-30';
+$plugin->release   = '2017-07-02';
 $plugin->maturity = MATURITY_STABLE;
 
 if ($useplugin != 2) {
-    $module = $plugin;
+    $module = $plugin
 }