Where are the log files?

You can find the client log files here:

1. Right-click Unturned in your Steam Library
2. Select Properties...
3. Hover over Manage
4. Click Browse local files
5. Open the Logs folder

The most recent or currently running file is "Client.log", and "Client_Prev.log" is the log from before the game was restarted.

If you are looking for server log files please refer to this article: Where are the dedicated server log files?