How to find your server logfiles on an on-premise installation

Go to the server where Planner or Display is installed.

Open a file explorer

The default path is

D:\Webdata\Default Website\sitename\App_Data

If your site isn't there, try checking a different partition or a different sitename.

Log.txt is todays file, and log1.txt etc are older logs.

The path is the same for both Planner and Display.