Steps to reproduce the issue

When you Triggering content plugins in your extension, you will get a php warning.

$params = new JObject;
JPluginHelper::importPlugin('content');
\JFactory::getApplication()->triggerEvent('onContentPrepare', array("com_component.{$view}", &$contents, &$params, 0));

Expected result

No warnings

Actual result

PHP Warning: Attempt to assign property 'jcfields' of non-object in \plugins\system\fields\fields.php on line 430

System information (as much as possible)

J3.8.4
PHP 7.2

Additional comments