How to fix Request validation failed for action “Magento\Framework\App\Action\Forward\Interceptor” for Controller

To controller add Magento\Framework\App\CsrfAwareActionInterface\CsrfAwareActionInterface and
public function createCsrfValidationException(RequestInterface $request): ?InvalidRequestException
{
return null;
}

public function validateForCsrf(RequestInterface $request): ?bool
{
return true;
}

Magento fix for “No Administrators role was found, data fixture needs to be run”

SQL queries

INSERT INTO authorization_role (role_id, parent_id, tree_level, sort_order, role_type, user_id, user_type, role_name) VALUES (1, 0, 1, 1, 'G', 0, '2', 'Administrators');
INSERT INTO authorization_rule (rule_id, role_id, resource_id, privileges, permission) VALUES (1, 1, 'Magento_Backend::all', null, 'allow');

Magento 2 debug controller match

Useful if your custom controller is not firing

Places to check:
vendor/magento/framework/App/FrontController.php

 while (!$request->isDispatched() && $routingCycleCounter++ < 100) {
            /** @var \Magento\Framework\App\RouterInterface $router */
            foreach ($this->_routerList as $router) {
                try {
                    $actionInstance = $router->match($request);
                    if ($actionInstance) {
                        $result = $this->processRequest(

vendor/magento/framework/App/Router/Base.php

  foreach ($modules as $moduleName) {
            $currentModuleName = $moduleName;

            $actionClassName = $this->actionList->get($moduleName, $this->pathPrefix, $actionPath, $action);
            if (!$actionClassName || !is_subclass_of($actionClassName, $this->actionInterface)) {
                continue;
            }

            $actionInstance = $this->actionFactory->create($actionClassName);
            break;
        }

USBAsp v 2.0 firmware for flashing AT89S51, AT89S52

main.hex firmware with an inversion of RESET pin:

https://drive.google.com/file/d/1QiRvCN29H0l-Kq0eJhdKs3WfHdrvEXrB/view?usp=sharing

source code:

https://drive.google.com/file/d/1-idzOalAeA77U9Ony_UZ1YfTT4d_M8j3/view?usp=sharing

avrdude.conf

https://drive.google.com/file/d/1bEraBArDpIUMMW7dt0KzH7qNNhkQd99W/view?usp=sharing

TARGET=atmega8

HFUSE=0xd9

LFUSE=0x9f
You can just flash the MCU without fuses

env for PlatformIO

[env:AT89S51]

platform = intel_mcs51

board = AT89S51

upload_protocol = custom

upload_command = sudo avrdude -c usbasp -p at89s51 -U flash:w:$SOURCE:i -C +./avrdude.conf

Magento 2 debug layout xml

/etc/events.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd"></event>
<event name="layout_generate_blocks_after">
    <observer name="layout_generate_blocks_after" instance="Module\Wishlist\Observer\Layout" />
</event>
</config>

Observer

<?php

/** * Create "Layout.php" at onlinecode/Dev/Model/Layout.php */

namespace Module\Wishlist\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;

class Layout implements ObserverInterface
{
    protected $set_logger;
    public function __construct(\Psr\Log\LoggerInterface $logger_cons)
    {
        $this->set_logger = $logger_cons;
    }
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $get_xml = $observer->getEvent()->getLayout()->getXmlString();
        $this->set_logger->debug($get_xml);
        $get_writer = new \Zend_Log_Writer_Stream(BP . '/var/log/layout_block.xml');
        $get_logger = new \Zend_Log();
        $get_logger->addWriter($get_writer);
        $get_logger->info($get_xml);
        return $this;
    }
}