diff --git a/assets/src/bundles/save/index.js b/assets/src/bundles/save/index.js
--- a/assets/src/bundles/save/index.js
+++ b/assets/src/bundles/save/index.js
@@ -345,7 +345,7 @@
     'duration': (v) => v + ' seconds'
   };
 
-  return mapFormatPerTypeFn[type](value);
+  return value === null ? null : mapFormatPerTypeFn[type](value);
 }
 
 export function displaySaveRequestInfo(event, saveRequestId) {