Please take a look at the following file. Right after opening, start an IPR session. Then assign a gradient ramp to the mask slot of the mask node that is assigned to the Vray Light: Instant crash.
https://transfer.px2.de/_ENcApl1QEdF5AR
Edit: Also happens when putting gradient ramps into Mix nodes while IPR runs.
https://transfer.px2.de/_ENcApl1QEdF5AR
Edit: Also happens when putting gradient ramps into Mix nodes while IPR runs.