Bad IL Format Exception when using Abstract Properties

IDE: Visual Studio 2015
Version: 9.0.97.2071
Target (If relevant): Net
Description:
When casting an object to an abstract parent and writing a abtract property using null propagation gives a Bad IL Format Exception

Expected Behavior:
The included app runs without errors

Actual Behavior:
The included app raises a Bad IL Format Exception

Steps:

Thanks, logged as bugs://77048

bugs://77048 got closed with status fixed.

Logged as bugs://i64815.

bugs://i64815 was closed as fixed.