I find the decals are hard to adjust in Visualize. After seeing this video that Brian Hillner posted, I think I would just use the texture method most of the time. BTW I hope Brian post more like this.
I also have noticed this issue, although it doesn't trigger every time. It seems to be file specific, but I will do more research with my R&D team to find the cause of the issue. Thanks for posting this.
Any other users experiencing this same issue of crashing when Copy/Paste decals in the Appearances Tab??