Issue after upgrade to 2.3.4

Question

I made an upgrade from v2.3.3 to v2.3.4 and now when I try to edit a product I receive this error:

Warning: Invalid argument supplied for foreach() in /vendor/magento/module-catalog/Model/ProductLink/CollectionProvider.php on line 185

Any idea where this error might be?

BR

Answer 1

in exception.log, I found this error

temando.CRITICAL: "accountId" is required. Enter and try again. {"exception":"[object] (Magento\\Framework\\Exception\\InputException(code: 0): \"accountId\" is required. Enter and try again. at /public_html/vendor/magento/framework/Exception/InputException.php:91)"}

after I search on google I found this solution https://magenaut.com/fix-error-after-disable-temando_shipping/

Answer 2

The Temando extension disabled can't fix the same problem for me. I found this variable $this->mapProviders is empty in /vendor/magento/module-catalog/Model/ProductLink/CollectionProvider.php file. This caused the problem. not sure what happened. I solved this problem by modifying the core magento file in /vendor/magento/module-catalog/Model/ProductLink/CollectionProvider.php. In getMap function, add this after if (!$types) {...}. So it'd be:

...
public function getMap(array $products, array $types): array
{
    if (!$types) {
        throw new \InvalidArgumentException('Types are required');
    }
   //FIX Warning: Invalid argument supplied for foreach() in /vendor/magento/module-catalog/Model/ProductLink/CollectionProvider.php on line 185
    if (!(is_array($this->mapProviders))) {
        $this->mapProviders = array(
            ObjectManager::getInstance()->create(LinkedMapProvider::class)
        );
    }
   ...
}
...

You need to import a few files as well on the top of this file:

use Magento\Catalog\Model\ProductLink\CollectionProvider\LinkedMapProvider;
use Magento\Framework\App\ObjectManager;

I know this fix is not clean as magento way. let me know if there is a better fix.