diff --git a/libraries/classes/Database/Designer/Common.php b/libraries/classes/Database/Designer/Common.php
index 562d35d1df..8f3e1ad31e 100644
--- a/libraries/classes/Database/Designer/Common.php
+++ b/libraries/classes/Database/Designer/Common.php
@@ -302,7 +302,7 @@ class Common
      *
      * @param int $pg pdf page id
      *
-     * @return string table name
+     * @return string|null table name
      */
     public function getPageName($pg)
     {
@@ -322,7 +322,7 @@ class Common
             DatabaseInterface::CONNECT_CONTROL,
             DatabaseInterface::QUERY_STORE
         );
-        return count($page_name) ? $page_name[0] : null;
+        return ( is_array($page_name) && isset($page_name[0]) ) ? $page_name[0] : null;
     }
 
     /**
@@ -370,7 +370,7 @@ class Common
     {
         $cfgRelation = $this->relation->getRelationsParam();
         if (! $cfgRelation['pdfwork']) {
-            return null;
+            return -1;
         }
 
         $query = "SELECT `page_nr`"
@@ -387,7 +387,7 @@ class Common
             DatabaseInterface::QUERY_STORE
         );
 
-        if (isset($default_page_no) && count($default_page_no)) {
+        if (is_array($default_page_no) && isset($default_page_no[0])) {
             return intval($default_page_no[0]);
         }
         return -1;
@@ -405,7 +405,7 @@ class Common
     {
         $cfgRelation = $this->relation->getRelationsParam();
         if (! $cfgRelation['pdfwork']) {
-            return null;
+            return -1;
         }
 
         $page_no = -1;
@@ -426,7 +426,7 @@ class Common
                 DatabaseInterface::CONNECT_CONTROL,
                 DatabaseInterface::QUERY_STORE
             );
-            if (isset($min_page_no[0]) && count($min_page_no[0])) {
+            if (is_array($min_page_no) && isset($min_page_no[0])) {
                 $page_no = $min_page_no[0];
             }
         }