Enable exception printing on the webpage in Magento2

It's similar to Magento 1, but local.xml.sample is located in pub/errors.

Just rename local.xml.sample to local.xml within pub/errors directory.

In Magento 2, local.xml.sample file is located in pub/errors/ You just need to rename local.xml.sample to local.xml

Now, the error log will not be generic but detailed like this

You can also turn on developer mode in Magento 2 by entering this line in Magento CLI: php bin/magento deploy:mode:set developer

Referrence source: http://magentoexplorer.com/magento-exception-printing-is-disabled-by-default-for-security-reasons-how-to-fix (This tutorial include both Magento 1 and Magento 2, scroll down you will see Debug for Magento 2)