System.NullReferenceException: 'Object reference not set to an instance of an object.'

[mahanteshvk]

return _Client.CreateDocumentQuery<TUser>(_Users.DocumentsLink, new FeedOptions { EnableCrossPartitionQuery = true }) .Where(u => u.DocId == "user").AsQueryable();

I am getting the below exception when the above piece of code gets executed System.NullReferenceException: 'Object reference not set to an instance of an object.'