Repro steps:

1. Open the provided project
2. Enter "Play Mode"
3. Click on the white cube in the "Scene" view ("CubeToDuplicate")
4. Press "Ctrl + D"
5. Look at the console

Expected result: For the console to output that the special command was validated ("Validate Duplicate") and executed ("Duplicate(ExecuteCommand)")(Check attached image "Photo 1(Proper)")
Actual result: The console doesn't output that the special command was validated or executed (Check attached image "Photo 2(Bug)")

Reproduce with: 2017.1.0b3 ,2017.1.0b2 ,2017.1.0b1 ,5.6.0p3 ,5.6.0p2 ,5.6.0p1 ,5.5.3p2 ,5.5.3p1
Regression introduced in: 2017.1.0a6
Did not reproduce on: 5.6.0f3 ,5.5.3f1 ,5.5.2f1 ,5.5.1f1

Note:
Added photos of what the console should output
EventType.ExecuteCommand doesn't execute the special command as well
The error happens inside of the "TestCommands" script file, at lines 21 and 27