Hi Loan,
We have analyzed your query. We suspect that you have added the native android NuGet package along with the forms android NuGet package in android project. Please remove the native android NuGet package if you have added in the android project mistakenly.
Also, please make sure that you have the same version of Xamarin.Forms NuGet in all your Xamarin.Forms projects and follow the below steps to resolve this issue.
1. Close the Visual Studio.
2. Delete bin and obj folder.
3. Open the Visual Studio again and rebuild the solution.
4. Now deploy the app in emulator or device.
Please let us know if you are still facing any issue in this.
Thanks,
Michael