fix: Handle case where event is null/undefined (#1254)

* fix: Handle case where `event` is null/undefined

* add changeset

.changeset/tiny-buckets-love.md

@@ -0,0 +1,5 @@
+---
+'rrweb': patch
+---
+
+Handle case where `event` is null/undefined

packages/rrweb/src/record/observer.ts

@@ -76,10 +76,11 @@ function getEventTarget(event: Event | NonStandardEvent): EventTarget | null {
     } else if ('path' in event && event.path.length) {
       return event.path[0];
     }
-    return event.target;
   } catch {
-    return event.target;
+    // fallback to `event.target` below
   }
+
+  return event && event.target;
 }
 
 export function initMutationObserver(