The Bugsplat is one of the most common errors encountered by SketchyPhysics users. Almost every user gets at least one some time or another.
Basically, a Bugsplat is the assigned name for when SketchUp crashes. The program will suddenly close, and a window will appear that has a picture of a squashed insect (hence the name) and an explanation that the program encountered a "Bugsplat" and needs to close.
There is a good chance that there is an auto-save file, even if you hadn't officially saved the file. However, you will still probably have lost some work, and auto-saves occasionally record the model in the middle of a simulation, rendering it final save a useless 3d screenshot.
Currently there is no solution or a way to avoid this.