Data type issue on Enumerable.Sum(TSource) method

[saf-itpro]

Environment: EF-Core 1.1, VS2015, Windows 10 (updated from Windows 7)

I'm getting the following error on LINQ Query shown below:
Unable to cast object of type 'System.Double' to type 'System.Nullable1[System.Single]'`

LINQ:
var totalFreight = (from cust in db.Customers join ord in db.Orders on cust.ordID equals ord.OrdID select ord.Freight).Sum();

NOTES:

1. I'm trying to follow these MSDN examples: 1 and 2

2. I've verified that Freight column in Orders table is of type float?. In VS2015, I've hover over ord.Freight in the above query to confirm the type of Freight column - that's is showing as float?

3. I've tried changing var to float? and double? and decimal?. But still the EXACT SAME error message as shown above.

[smitpatel]

@maumar

[maumar]

dupe of #7136 which will be fixed in the next release (2.0.0-preview1)