OXID eShop admin module for displaying the file exception_log.txt
Unzip the complete file with all the folder structures and upload the content of the folder copy_this to the root folder of your shop. After this navigate in the admin backend of the shop to "Extension - Modules". Select the module and click on "Activate". If you open the menu "System", you will see the the new menu item "Exception Log".
Tested in OXID version 4.7, 4.8 and 4.9.