Happens when using the sliders. When inserting numeric values, all good. When sliding > crash. Happens in heavy scenes. Just started a new project, scene is still less then 100K poly's, no Forest Packs or anything yet, just geometry, works so far. But IR still tends to hang when for example rotating the daylight compass with the HDRI-environment map linked to it (RadToDeg Z_Rotation / 360.0 through parameter wiring) - Almost like he needs to reload the hdri every +/- 30° degrees of rotation.
Just saying, the IR is not a "trusted" tool atm.. To unstable in our heavier scenes, and not handy enough for lighting, it's faster to do a normal render and pressing F9.