The error is quite generic and there could be varied reasons for it. I suggest you try following to ensure your MAUI environment is set up correctly:
- Try an out-of-the box MAUI app using Visual Studio template
- Try creating a new project using ArcGIS Maps SDK Template. If yo haven't installed templates yet, you can look them up in Extensions dialog box from Visual Studio
- Ensure you have a valid API Key to access base maps.
Let me know if this helps or is more meaningful to determine the cause of the error.