complex query causes NullReferenceException

[alexk8]

[preview7]
Code like this used to work earlier

context.Set<SaleItem>()
                //.Where(x => x.document.customer == aCustomer) // broken
                .Where(x => x.document.customer.id == 123) //new
                .GroupBy(x => new { x.Goods, x.document.currency } )
                .Select(x => new
                {
                    x.Key.Goods,
                    x.Key.currency,
                    total = x.Sum(x => x.Amount*x.Price)
                })
                .ToList();

Now it causes NullReferenceException - "Object reference not set to an instance of an object."

Stack trace

   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.EntityProjectionExpression.GetProperty(IProperty property)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.SqlExpressions.SelectExpression.BindProperty(ProjectionBindingExpression projectionBindingExpression, IProperty property)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.BindProperty(EntityShaperExpression entityShaperExpression, IProperty property)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.BindProperty(Expression source, String propertyName)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.VisitMember(MemberExpression memberExpression)
   at System.Linq.Expressions.MemberExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.VisitMember(MemberExpression memberExpression)
   at System.Linq.Expressions.MemberExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at Microsoft.EntityFrameworkCore.SqlServer.Query.Pipeline.SqlServerSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at System.Linq.Expressions.BinaryExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalSqlTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateExpression(Expression expression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateLambdaExpression(ShapedQueryExpression shapedQueryExpression, LambdaExpression lambdaExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass9_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

Full Code

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using System;
using System.Linq;

namespace ConsoleTester
{

    public class Customer
    {
        public int id { get; set; }
        public string Name { get; set; }
    }
    public class SaleDocument
    {
        public int id { get; set; }
        public int currency { get; set; }
        public DateTime date { get; set; }
        //public string Num { get; set; }
        public Customer customer;
    }
    public class SaleItem
    {
        public int id { get; set; }
        public SaleDocument document { get; set; }
        public string Goods { get; set; }
        public decimal Amount { get; set; }
        public decimal Price { get; set; }
    }

    class MyDbContext : DbContext {

        ILoggerFactory loggerFactory;
        public MyDbContext(ILoggerFactory loggerFactory)
        {
            this.loggerFactory = loggerFactory;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);
            string msconnString = "Server=(localdb)\\mssqllocaldb;Database=TMP-1BBF_08;Trusted_Connection=True;MultipleActiveResultSets=true";
            optionsBuilder.UseSqlServer(msconnString);
            optionsBuilder.UseLoggerFactory(loggerFactory);
        }
        protected override void OnModelCreating(ModelBuilder M)
        {
            base.OnModelCreating(M);
            M.Entity<Customer>();
            M.Entity<SaleDocument>();
            M.Entity<SaleItem>();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            var conf = new ConfigurationBuilder().AddJsonFile("appsettings.json", true).Build();
            IServiceCollection services = new ServiceCollection();
            services.AddLogging(bld=>bld.AddConfiguration(conf).AddConsole());
            services.AddDbContext<MyDbContext>();
            using (var scope = services.BuildServiceProvider().CreateScope())
            {
                var context = scope.ServiceProvider.GetRequiredService<MyDbContext>();
                context.Database.EnsureCreated();
                if (!context.Set<Customer>().Any())
                {
                    var customer = context.Add(new Customer { Name = "Alice" }).Entity;
                    var doc = context.Add(new SaleDocument { customer = customer, date = DateTime.Now, currency = 810 }).Entity;
                    var goods = context.Add(new SaleItem { document = doc, Goods = "Butter", Amount = 1, Price = 10 });
                    context.SaveChanges();
                }

                var results = context.Set<SaleItem>()
                    .Where(x => x.document.customer.id == 123) // other error when no "Where"
                    .GroupBy(x => new { x.Goods, x.document.currency })
                    .Select(x => new
                    {
                        x.Key.Goods,
                        x.Key.currency,
                        total = x.Sum(x => x.Amount * x.Price)
                    })
                    .ToList();
                Console.WriteLine(results.Count);
            }
        }
    }
}

And if I comment out '.Where(...)' clause I get other error - System.InvalidOperationException: 'Operation is not valid due to the current state of the object.'

full stack

System.InvalidOperationException: 'Operation is not valid due to the current state of the object.'

   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateGroupBy(ShapedQueryExpression source, LambdaExpression keySelector, LambdaExpression elementSelector, LambdaExpression resultSelector)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass9_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

I thought I has been fixed in preview7

[los93sol]

I have the same issue as well...

System.InvalidOperationException: Operation is not valid due to the current state of the object.
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateGroupBy(ShapedQueryExpression source, LambdaExpression keySelector, LambdaExpression elementSelector, LambdaExpression resultSelector)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.Pipeline.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass12_0`1.<ExecuteAsync>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)

[ajcvickers]

@smitpatel to find duplicate

[smitpatel]

Duplicate of #15855

[smitpatel]

Duplicate of #15249 too

[alexk8]

I appologize, but

1. 15855 has been closed some time before preview7 was released, but it's still there in preview7
2. NRE is not the same as IOE

Sorry, but all that made me think that is not a duplicate.
However, it's fixed in preview8 nightly builds, so now it's closed justly. Thanks

[smitpatel]

15855 has been closed some time before preview7 was released, but it's still there in preview7

It could be true that issue has been closed before preview7 released but building a product to release takes some time (due to build + verification) so it may not contain the fix directly based on timeline. But if you look at the milestone then it will tell which public release the fix will be in.