What is an error_log file:
An Error_log displays information about the error that affects the functionality of the entire firewall.
An error_log file can be found in the root directory. This file is in several hundred megabytes in size and it grows by few megabytes in size. In this file contains all the errors that occur when accessing a cPanel related site over HTTP or https. This file contains the information about every error, the time it happened and the page where the error had happened. So this file will be more helpful in fixing the errors. This file can be deleted and a new one can be created when needed again.
Which directory contains cPanel and WHM’s error_log file:
cPanel access logs for both cPanel and WHM.
All common logs can be located in the directory
Error_log file can be located in the directory