If the new save file did not solve the problem, you can download the save file backups from the Cloud:
This will recover the Replays, Training Sequences, Video Settings, and Tutorial Completion Data:
- Return to the Home Menu.
- Highlight Rocket League.
- Press the + button on your JoyCon to open the Rocket League software menu.
- Select Save Data Cloud.
- Select the desired user.
- Select Download Save Data.
If you are trying to solve a Load Failure error in Rocket League and this did
not help, try the next step: How do I reinstall Rocket League on Nintendo Switch?