Fatal Error

Hey,
I got 2 websites, one for test and the second is main.
On my tes site everything is fine but when i go on my main page and im trying to access
plugin i see something like this:

Fatal error: Call to undefined method UserAccessManager\Controller\Backend\UserGroupController::traitRender() in […]/wp-content/plugins/user-access-manager/src/Controller/Controller.php on line 149

which goes to:

public function render()
{
$this->processAction();
$this->traitRender(); <– This one
}

What can i do to make this plugin work?