My OS W10 CHT, using windows app to login, but the screen is always loading, cant login successful.

I've got you covered today, albert-hui-amtra.

Let's perform a few troubleshooting steps to fix this login issue. Doing this will help us keep the application compatible with your OS version. Let's start by resetting the app data to clear the cache and refresh it into its default state.

Here's how to do that:

1. Click Help on the navigation bar at the top.
2. Select on Reset App Data.
   
3. Allow a moment for the process to complete, and then close the app.
4. Be sure to right-click the app and Run as Administrator when re-opening.

If the problem continues after performing these steps above, you may uninstall and reinstall the application to reload the data. You may also check out this link attached for more troubleshooting actions to be taken when you've encountered issues while using the app: QuickBooks App for Windows and Mac: General support.

Feel free to drop me a reply below if there's anything I can help you with. Wishing you all the best!