Fatal error: Uncaught Error: Class "Atk4\Core\Tests\FieldMock" not found in /home/.sites/site4/wwwroot/web/4.0/ui/vendor/atk4/core/tests/FieldMockCustom.php:12
Stack trace:
#0 {main}
thrown in /home/.sites/site4/wwwroot/web/4.0/ui/vendor/atk4/core/tests/FieldMockCustom.php on line 12