[WinRT] Qt Purchasing - Unable to handle transactions

I downloaded and installed the Qt 5.8 beta WinRT MSVC2015 offline installer from my Qt account. I am using the community version of VS 2015 running on Windows 10 Pro.

I have tried the QtHangman example and it seems that transactions are not recognized as datatypes in QML. I am using the simulation file that is part of the example.

When I purchase something I get this:

qt.winrtrunner.app: QMetaMethod::invoke: Unable to handle unregistered datatype 'qt_WinRTTransactionData'

When I restore purchases, for

console.log("timestamp: " + transaction.timestamp); 

I get:

qt.winrtrunner.app: timestamp: Invalid Date