Fix Genshin Impact Error Code 9203 on Windows 10 (4/8/21 Re-updated)

Here's how to Fix Genshin Impact Error Code 9203 on Windows 10.

4/8/21 Added (Troubleshooting Tips for Android players): 1) shut down then reboot your device; 2) restart your router (if any); 3) check your internet connection and ensure you're using a fast, stable one. If not, Google how to improve your slow web connection; 4) update your Genshin Impact app & your Android system in time.

[mohammodafif]

I dont have a problem on luncher but in-game when it progresses it says the download file is missing how can I fix this?