How to create a new save file to troubleshoot Rocket League Load Failure errors on PC?
The steps below will help you create a new Save File in Rocket League:
Close Rocket League
Launch the Epic Games Launcher
Select Settings from the menu
Uncheck the Enable Cloud Saves checkbox
Launch Rocket League to generate a new save file
Close Rocket League and relaunch Rocket League
You should now have a newly created Save File.
If you are trying to solve Rocket League Load Failure errors on PC and this did not help, try the next step: How to recover backed-up replays and training sequences for Rocket League on PC?