Fatal error: Uncaught Error: Class 'JsonSchema\Uri\Retrievers\AbstractRetriever' not found in /var/www/html/simplesamlphp/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/Retrievers/PredefinedArray.php:21
Stack trace:
#0 {main}
  thrown in /var/www/html/simplesamlphp/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/Retrievers/PredefinedArray.php on line 21