You may run into this issue while installing a game due to the launcher unable to relocate a file while downloading.
Disable background applications
Make sure you disable any background applications that could be interfering with the Epic Games Launcher as outlined in the article: How do I disable background applications?
Uninstall and reinstall the game
Reinstalling your game may resolve the issue.
- Open the Epic Games Launcher.
- Click on the Library.
- Locate your game and click on the three dots next to it.
- Click on Uninstall.
Once the uninstall completes, click on the game to begin the installation process again.