Assets file '\obj\project.assets.json' doesn't have a target for 'net8.0'. Ensure that restore has run and that you have included 'net8.0' in the TargetFrameworks for your project.

✅ 1. Clean the Build Artifacts

Delete the following folders from each project directory:

• bin/

• obj/

You can do this via command line in the root of your solution:

Or manually delete:

✅ 2. Restore the Solution

After cleaning, restore NuGet packages with:

This will regenerate the project.assets.json file using the updated net9.0 target.

✅ 3. Double-Check All Project Files

Open every .csproj file and make sure that:

• TargetFramework or TargetFrameworks is updated to net9.0 only:

If using multiple target frameworks:

✅ 4. Check for Global.json

If your solution contains a global.json file (at the root or in any directory), make sure it doesn't lock your SDK version to 8.0.

Here's an example:

Update it to match a .NET 9.0 preview SDK you have installed:

Or simply delete the global.json if you want to use the system default.

✅ 5. Ensure .NET 9.0 SDK is Installed

Run:

Make sure something like 9.0.xxx appears in the list. If not, download the .NET 9 SDK from:

🔗 https://dotnet.microsoft.com/en-us/download/dotnet/9.0

✅ 6. Rebuild the Solution

After following the above, rebuild your solution:

✅ Optional: VS Settings (if using Visual Studio)

If you're using Visual Studio:

• Ensure you're on Visual Studio 2022 17.10+ or VS 2025 Preview, which supports .NET 9.

• Go to Tools > Options > Preview Features and enable .NET 9 features if needed.

🔁 Summary

• Clean bin and obj

• Ensure all .csproj files use net9.0

• Check/remove global.json

• Confirm .NET 9 SDK is installed

• Restore and rebuild

Thanks. I resolved by doing above steps.