ErrorMSB4018 The "ResolvePackageAssets" task failed unexpectedly.
NuGet.Packaging.Core.PackagingException: Unable to find fallback package folder 'C:\Microsoft\Xamarin\NuGet\'.
at NuGet.Packaging.FallbackPackagePathResolver..ctor(String userPackageFolder, IEnumerable`1 fallbackPackageFolders)
at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(IEnumerable`1 packageFolders)
at Microsoft.NET.Build.Tasks.NuGetPackageResolver.CreateResolver(LockFile lockFile)
at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheWriter..ctor(ResolvePackageAssets task)
at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader.CreateReaderFromDisk(ResolvePackageAssets task, Byte[] settingsHash)
at Microsoft.NET.Build.Tasks.ResolvePackageAssets.CacheReader..ctor(ResolvePackageAssets task)
at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ReadItemGroups()
at Microsoft.NET.Build.Tasks.ResolvePackageAssets.ExecuteCore()
at Microsoft.NET.Build.Tasks.TaskBase.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()ConsoleApp1C:\Program Files\dotnet\sdk\3.1.201\Sdks\Microsoft.NET.Sdk\targets\Microsoft.PackageDependencyResolution.targets234