Magento2 : Getting Error when enabled Flat catalog Category and Product

Question

I am using magento 2.3.2. My site takes too much to load. I enabled flat catalog category and Flat catalog product. See https://prnt.sc/pgr3xu. But on site when i click on any product it gives me error "Invalid argument supplied for foreach() in /var/www/html/ihouzit/app/code/Mageplaza/Search/Helper/Data.php on line 345" See https://prnt.sc/pgr3zx What can be the issue.

Getting error from this function

protected function getCategoryOptions($category, &$options, $level, $htmlPrefix = '')
{
    if ($level <= 0) {
        return $this;
    }
    $level--;

    $options[$category->getId()] = $htmlPrefix . $category->getName();

    $htmlPrefix .= '- ';
    foreach ($this->getChildCategories($category) as $childCategory) {
        $this->getCategoryOptions($childCategory, $options, $level, $htmlPrefix);
    }

    return $this;
}

Answer 1

Update your function to this, this should work

protected function getCategoryOptions($category, &$options, $level, $htmlPrefix = '')
{
    if ($level <= 0) {
        return $this;
    }
    $level--;

    $options[$category->getId()] = $htmlPrefix . $category->getName();

    $htmlPrefix .= '- ';
    $childCategories = $this->getChildCategories($category);
    if(count($childCategories) > 0){
        foreach ($childCategories as $childCategory) {
            $this->getCategoryOptions($childCategory, $options, $level, $htmlPrefix);
        }
    }

    return $this;
}

Hope this will resolve your issue.