Fatal error: Uncaught Error: Class 'JsonSchema\Constraints\Constraint' not found in /data/htmlwww/common/jpgraph/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/SchemaConstraint.php:24 Stack trace: #0 {main} thrown in /data/htmlwww/common/jpgraph/vendor/justinrainbow/json-schema/src/JsonSchema/Constraints/SchemaConstraint.php on line 24