Fatal error: Uncaught Error: Interface 'JsonSchema\Uri\Retrievers\UriRetrieverInterface' not found in /var/www/html/simplesamlphp/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/Retrievers/AbstractRetriever.php:19
Stack trace:
#0 {main}
  thrown in /var/www/html/simplesamlphp/vendor/justinrainbow/json-schema/src/JsonSchema/Uri/Retrievers/AbstractRetriever.php on line 19