Try deleting the “webcache” folder along with its related subfolders, please:
- Press the Windows key + R on your keyboard to open the Run dialog box.
- Type %localappdata% and press Enter. This will open up the Local AppData folder.
- Find and open the “webcache” folder.
- Delete the “webcache” folder as well as its related subfolders, i.e. “webcache_4147” and “webcache_4430”.
- Restart your computer and try launching the game again.
If the above doesn't help, try installing the game and the Epic Games launcher on the same hard-drive (e.g. the C: drive), please.