How to diagnose the «We're sorry, an error has occurred while generating this email» failure

dmitrii_fediuk · January 28, 2016, 8:37am

magento/magento2/blob/720667e/app/code/Magento/Email/Model/Template/Filter.php#L962-L974


try {
    $value = parent::filter($value);
} catch (\Exception $e) {
    // Since a single instance of this class can be used to filter content multiple times, reset callbacks to
    // prevent callbacks running for unrelated content (e.g., email subject and email body)
    $this->resetAfterFilterCallbacks();


    if ($this->_appState->getMode() == \Magento\Framework\App\State::MODE_DEVELOPER) {
        $value = sprintf(__('Error filtering template: %s'), $e->getMessage());
    } else {
        $value = __("We're sorry, an error has occurred while generating this email.");
    }
    $this->_logger->critical($e);

As you can see from the code:

The exception is occured while executing the \Magento\Framework\Filter\Template::filter() method

The error could be not related to a email (the poor message is a Magento 2 issue), but related to a {{}} CMS directive.
You can enable the developer mode to get the actual exception’s message on the screen instead of the poor generic message.
You can also see the actual exception’s message in the exception log file.