Magento 2.3.5p2 - Invalid security or form key. Please refresh the page after installing banner slider

Question

I downloaded BannerSlider from GitHub and pasted the files into the app> code> Magestore. in the admin panel, it showing the manage options but when I click it says Invalid security or form key.

Please refresh the page. I tried changing max input vars to 10000 in php.ini file but no change.

Can anyone help me I am new to Magento I am using PHP 7.3.2.

Answer 1

Considering you already tried increasing the max input vars, i recomend you to also:

• Run on your terminal:

  php bin/magento setup:upgrade; php bin/magento setup:di:compile; php bin/magento cache:clean; php bin/magento cache:flush;

• Clear your browser cookies;

Usually this error occurs when magento can't recognize the form key in it's validation, either by not receiving it, or by being invalid.

Answer 2

Please add following code in your admin controller :

protected $request;
protected $formKey;

public function __construct(
\Magento\Framework\App\Action\Context $context,
\Magento\Framework\Data\Form\FormKey $formKey,
\Magento\Framework\App\Request\Http $request
) {
    $this->request = $request;
    $this->formKey = $formKey;
    $this->request->setParam('form_key', $this->formKey->getFormKey());
    parent::__construct($context);
}