Fixed #2687

CHANGELOG-v3.md

@@ -6,6 +6,7 @@
 - Fixed an error that could occur in the Control Panel if any plugins with licensing issues were installed. ([#2691](https://github.com/craftcms/cms/pull/2691))
 - Fixed a bug on the Plugin Store’s Payment screen where the “Use a new credit card” radio option would not get selected automatically even if it was the only one available.
 - Fixed a bug where `craft\web\assets\vue\VueAsset` didn’t respect the `useCompressedJs` config setting.
+- Fixed an error that occurred when saving a Single entry over Ajax. ([#2687](https://github.com/craftcms/cms/issues/2687))
 
 ## 3.0.1 - 2018-04-04
 

src/controllers/EntriesController.php

@@ -569,7 +569,10 @@ public function actionSaveEntry()
                 $return['cpEditUrl'] = $entry->getCpEditUrl();
             }
 
-            $return['authorUsername'] = $entry->getAuthor()->username;
+            if (($author = $entry->getAuthor()) !== null) {
+                $return['authorUsername'] = $author->username;
+            }
+
             $return['dateCreated'] = DateTimeHelper::toIso8601($entry->dateCreated);
             $return['dateUpdated'] = DateTimeHelper::toIso8601($entry->dateUpdated);
             $return['postDate'] = ($entry->postDate ? DateTimeHelper::toIso8601($entry->postDate) : null);