Just wanted to report on possible fix for future. When using IPR with RC object inside the scene it crashes while doing any operation. if i just want to render with IPR it works, but from the moment i do something even remotely simple like switching viewports, it goes down.
I tested it also with only one very simple RC object in the scene.
Please note that IPR and V-Ray 3.5 specific support will be included only in RailClone 3.x, which is currently in beta.
We have not plans to make more changes to the RailClone 2.x branch.