These NU1101 errors in your Blazor project suggest that the required NuGet packages aren't being found in the configured sources. To resolve this, Update NuGet Package Sources in Visual Studio:
- Go to Tools > Options > NuGet Package Manager > Package Sources
- Add or enable the official NuGet source:
- Name: nuget.org
- Source: https://api.nuget.org/v3/index.json
