\Magento\Backend\Model\View\Result\RedirectFactory already exists in context object. How to solve this problem in magento 2?
You may have injected
\Magento\Backend\Model\View\Result\RedirectFactory this class which is already available in your injected class so it shows such an error
you can get the RedirectFactory using context object
$this->redirectFactory = $context->getRedirectFactory();
and then you can use your redirectFactory as you were.