Fatal error: Uncaught Error: Class "Kirby\Panel\Model" not found in /volume1/web/public/kirbi/kirby-4.1.0/src/Panel/Page.php on line 20

Error: Class "Kirby\Panel\Model" not found in /volume1/web/public/kirbi/kirby-4.1.0/src/Panel/Page.php on line 20

Call Stack:
    0.0048     354040   1. {main}() /volume1/web/public/kirbi/kirby-4.1.0/src/Panel/Page.php:0