for the most recent crash report attached , I had created a papagayo seq using the cl pg tab, then closed xl , reopened that seq , rendered etc, toggled the nodes , then I dropped an "on" effect in a blank cell. (There is only one model defined).
(I may have tried to delete the On effect just dropped or undo it when it crashed).
For the earlier crash report , I was also fiddling about in the same area (with nodes toggled on) trying to understand whether I could edit the papagayo that had been "imported" by the earlier step, but don't remember exactly what key I had pressed when it crashed as I tried a few . Attaching in case it is of use.