diff -r dbb941b9fb66 -r 9cffc7f32f14 server/src/app/Libraries/Transcript/TranscriberTranscriptConverter.php
--- a/server/src/app/Libraries/Transcript/TranscriberTranscriptConverter.php	Sat Dec 17 23:43:28 2016 +0100
+++ b/server/src/app/Libraries/Transcript/TranscriberTranscriptConverter.php	Sun Dec 18 01:13:51 2016 +0100
@@ -170,12 +170,14 @@
                 'id' => $this->document->getId()."_sctn".sprintf("%03d", $sectionIndex+1),
                 'items' => $sectionItems,
                 'meta' => [
-                    'corpus:topic'=> ["id-ref" => $this->topicIds[$sectionNode->getAttribute('topic')]],
                     'corpus:begin' => floatval($sectionNode->getAttribute('startTime'))*1000,
                     'corpus:end' => floatval($sectionNode->getAttribute('endTime'))*1000,
                 ]
             ];
-
+            $topicRef = $sectionNode->getAttribute('topic');
+            if(!empty($topicRef) && array_key_exists($topicRef, $this->topicIds)) {
+                $section['meta']['corpus:topic'] = ["id-ref" => $this->topicIds[$topicRef]];
+            }
             array_push($this->lists, $section);
         }
     }