Couple of questions:
1. There are no corona materials when loaded from your libraries. Is this normal or I have setup something wrong?
I can only see standard, vray, mentalray and sometimes thea.
2. From what I read at the corona forums, when assigning a non-vray material to a RC object it will automatically disable Instancing Engine.
This is not the case with my setup.
Using RC 2.7.4
Corona 1.5 trial
Max 2017 SP3