Magento\Ui\TemplateEngine\Xhtml\Result::__toString() must not throw in Magento 2.1

Question

After I created some product in magento backend, there is an error.

Method Magento\Ui\TemplateEngine\Xhtml\Result::__toString() must not throw an exception, caught Error: Call to undefined method Magento\Framework\Data\Collection::__sleep() in /var/www/vhosts/plchk/vendor/magento/module-ui/Component/Wrapper/UiComponent.php on line 0

By searching the net, I found Magento 2 Impossible To Trace Admin Grid Error: Fatal error: Method Magento\Ui\TemplateEngine\Xhtml\Result::__toString() must not throw an exception.

Using this method, I found that the 'product.form.configurable.matrix' is the cause of problem.

I changed

    protected function _toHtml()
{
    foreach ($this->getChildNames() as $childName) {
        $childBlock = $this->getLayout()->getBlock($childName);
        if ($childBlock) {
            $wrapper = $this->blockWrapperFactory->create([
                'block' => $childBlock,
                'data' => [
                    'name' => 'block_' . $childName
                ]
            ]);
            $this->component->addComponent('block_' . $childName, $wrapper);
        }
    }

    $result = $this->component->render();
    return (string)$result;
}

to

 protected function _toHtml()
    {
        foreach ($this->getChildNames() as $childName) {
            $childBlock = $this->getLayout()->getBlock($childName);
            if ($childBlock) {
                $wrapper = $this->blockWrapperFactory->create([
                    'block' => $childBlock,
                    'data' => [
                        'name' => 'block_' . $childName
                    ]
                ]);
                if($childName != 'product.form.configurable.matrix'){
                    $this->component->addComponent('block_' . $childName, $wrapper);
                } else {
                }


                //var_dump($childName);
            }
        }
        $result = $this->component->render();
        return  (string) $result;
    }

Now, I can load the admin/product/edit page but I cannot save the product. Anyone got a solution?

Answer 1

I have also face this issue, then I run commands

c:flush;c:clean;setup:upgrade;setup:di:compile

But still face the same Issue, then I have to remove the generated folder then it resolved.

In the magento root directory run this

rm -rf generated/*

Hope it help