Diagnosing issues using logging

If you are experiencing any problems when running rFactor 2 on your system, it's obviously important to describe your problem as accurately as possible so we can try to reproduce it internally. A step by step explanation would be very helpful. If you have someone else that can validate those steps, that's even better. Apart from describing such steps, there are various different types of logs you can enable that help us diagnose problems in more detail. This page gives a brief overview of each, its purpose and how to enable and send them.

As a starting point, if your issue is not performance related, take a look at trace logging below. If it is performance related, a good first step is to enable a little graph with Ctrl-C that shows two horizontal bars:

  1. A purple bar, representing physics, that should never be close to 100%. This bar indicates how much time is spent doing physics calculations (which are done on your CPU). If that bar behaves erratic and shoots up to 100%, go to the section on performance logging and try to capture the issue with that enabled.
  2. A green bar, representing graphics, that (unless you cap your framerate) should be close to 100%. This bar indicates how much time is spent rendering graphics (mostly done on your GPU). If the bar behaves erratic, or somehow your graphics don't appear to be smooth, go to graphics logging.

Trace Logging

The trace log contains a step by step overview of events that happen inside the code of rFactor 2. They tell us about series, cars and tracks that load, settings that get applied or saved and many other details. Typically they can help us figure out if anything out of the ordinary happened in the game code as they typically also record error conditions or other problems we can detect. They are useful in situations where the simulation does not do what you expect it to or even crashes. They are typically not useful for performance related issues.

How to enable?

Trace logging is enabled via a command line argument. In the Launcher you can add this argument for single or multiplayer or even devmode. If you are launching rFactor 2 from a shortcut you can add it there too. The syntax is: +trace=2

What to send?

Trace logs end up in the UserData\Log folder of your rFactor 2 install. The latest one is called "trace.txt" unless rFactor 2 crashed during the latest run. Older ones are typically marked with a timestamp in the name. When in doubt, sort them by modification date. Just send us that text file along with your description of the problem. If you have an in-game time, feel free to mention it. That might save us wading through many lines. If they are large, feel free to zip them.

Graphics Logging

The graphics logging keeps track of how long we typically spend in what part of the graphics code, breaking down the frame time (=time to render a single image) in different steps, such as shadow drawing, reflection calculation, etc. 

How to enable?

  1. Make sure you are in your car, driving.
  2. Hit Ctrl-F to enable the frame rate information in the top left corner.
  3. Use Left Shift-Space to start recording. You should see a message "RECORDING" on screen. This recording will continue for some time and then stop again.

What to send?

Graphics logs end up in the UserData\Log folder of your rFactor 2 install. Sort the files by modification date. All these logs are start with "PerfLog" and end with ".txt". Send us that text file along with your description of the problem. If you have an in-game time, feel free to mention it. If they are large, feel free to zip them.

Performance Logging


This logging keeps track of how long we typically spend in what part of the physics code, breaking that down into different steps, which allows us to see for example what the code was doing when physics froze, such as calculating player physics, doing collisions, talking to your wheel, inside plugins, etc. More information on this feature is available in the following forum thread: https://forum.studio-397.com/index.php?threads/logging-out-of-realtime-physics-freezes-public-test.62687/

How to enable?

Open your player.json file, located in UserData\player, with a text editor and search for the line that says "RealTimeLogging":0, and change it to read "RealTimeLogging":1,

What to send?

Performance logs end up in the UserData\Log folder of your rFactor 2 install. We keep the last 5 sessions. There should be two files per session, named after the session and ending with the extension .csv and you need to send us both for diagnosis. If they are large, feel free to zip them.