Fix fatal error.

main/exercice/exercise.php

@@ -117,10 +117,10 @@ if (!empty($gradebook) && $gradebook == 'view') {
 $nameTools = get_lang('Exercises');
 $errorXmlExport = null;
 if ($is_allowedToEdit && !empty($choice) && $choice == 'exportqti2') {
+    require_once api_get_path(SYS_CODE_PATH).'exercice/export/qti2/qti2_export.php';
+    require_once api_get_path(LIBRARY_PATH).'pclzip/pclzip.lib.php';
 
     $export = export_exercise_to_qti($exerciseId, true);
-
-    require_once api_get_path(LIBRARY_PATH).'pclzip/pclzip.lib.php';
     $archive_path = api_get_path(SYS_ARCHIVE_PATH);
     $temp_dir_short = api_get_unique_id();
     $temp_zip_dir = $archive_path.$temp_dir_short;