How to diagnose the «Imported resource (image) could not be downloaded from external resource due to timeout or access permissions» failure on a product import? [Administration] (2)
How to diagnose Magento 2 errors [How To] (3)
What does mean «CVV2 Mismatch: 15004» for a PayPal transaction? [Payment] (2)
How to log an exception? [Development] (1)
The exceptions are loggged into the var/log/exception.log file [Administration] (2)
How does \Magento\Framework\Logger\Monolog::critical() work? [Development] (2)