What is “Exception printing is disabled by default for security reasons”?
As we have explained in this similar tutorial There has been an error processing your request, this is a common error message that you will encounter when working with Magento. This message itself is NOT an error, but a notification on some errors occurring in your system.
We usually see this error message when installing a new Magento theme/module. The conflict between some components of Magento cause this error and Magento cannot operate properly. Another common cause is related to cache folder of Magento.
What it looks like in Magento 1:
In Magento 2:
How to solve this?
There are two main ways to solve this error message: (1) clearing your cache and (2) enable printing errors. Now we’ll go into details on each solution.
1. Clearing your cache
Access your Magento installation folder, go to var/cache and delete all the files.
Then, refresh your Magento site to see if the error message is gone.
Don’t skip this guide to know how to Enable/Disable OR Clear Cache in your Magento 2-based online stores.
2. Enable printing errors
If the above method doesn’t work, then you need to enable printing errors to find out what the exact problems are and solve all of them.
As can be seen in the error page, you will need to check error log record number xxxxxxx. Error log files of Magento are generated in /var/report (Magento 1) and /var/log (Magento 2). You will need an FTP client like Filezilla to open the file and read error log.
You can also enable printing error by navigating to Magento/errors (Magento 1) or /pub/errors/ (Magento 2), you will find a file named local.xml.sample. Rename this file to local.xml. Next, flush Magento cache and reload the error page. Now you will see error displayed as below.
Now you just need to solve the error displaying on the page. After that, the “There has been an error processing your request” message will disappear.