How to diagnose the «We can't process your request right now» failure for the contact form?

dmitry_fedyuk · April 16, 2016, 2:20pm

magento/magento2/blob/072a1ae/app/code/Magento/Contact/Controller/Index/Post.php#L70-L77


} catch (\Exception $e) {
    $this->inlineTranslation->resume();
    $this->messageManager->addError(
        __('We can\'t process your request right now. Sorry, that\'s all we know.')
    );
    $this->_redirect('contact/index');
    return;
}

As you can see, there is no logging for the exception.
You should log the exception or set a breakpoint.