How to locate ESS and Workflow Engine (WFE) log files
This help page is for on premise IT team and explains how they can find the latest ESS and WFE (Workflow Engine) Log.txt files.
Firstly, please ask employee or manager to reproduce the problem and note the date and time.
Your IT team can then locate the Log files from IIS.
Right-click on each application in IIS to Explore and look in Logs folder for latest Log.txt file. 
Please copy these files to another location and rename them to ESSLog.txt and WFELog.txt.
Reply to support email with both log files attached and the date and time of the error.