Add an safeguard for the color scheme option during the update

diff --git a/wcfsetup/install/files/lib/system/style/StyleHandler.class.php b/wcfsetup/install/files/lib/system/style/StyleHandler.class.php
index c91c17ebdbe63ade03b0a3fc8b13aba77cdd0e1a..e1a575a82e20dbe69439fbb297fbdc0f7374e99e 100644 (file)
--- a/wcfsetup/install/files/lib/system/style/StyleHandler.class.php
+++ b/wcfsetup/install/files/lib/system/style/StyleHandler.class.php
@@ -304,6 +304,6 @@ class StyleHandler extends SingletonFactory
             return 'system';
         }
 
-        return WCF::getUser()->getUserOption('colorScheme');
+        return WCF::getUser()->getUserOption('colorScheme') ?? 'system';
     }
 }