Uncaught PHP Exception TypeError: "call_user_func_array(): Argument #1 ($callback) must be a valid callback, class Drupal\Core\Render\Element\Date does not have a method "processDate"" at /core/lib/Drupal/Core/Form/FormBuilder.php line 1012

It’s hard to say what’s going on here. Can you please obtain a stack trace?

This issue is resolved now after adding the pg_trm extension.
Thank you for your Support.