SketchUp 2015 crashes whenever I try to explode a group

Using SketchUp 2015 (v. 15.2.685 64-bit) with Windows 8.1 64-bit (6.3, Build 9600). Had been working fine up until a few days ago when the latest Windows updates were installed. Previous projects I was working on now crash when I try to explode a group. I’ve tried copying just a few items to a new project. Sometimes I can then explode a single item initially, but after then it crashes every time. All my drivers are up to date. No extensions are installed. I’ve even removed and reinstalled SketchUp. Any ideas what the problem might be?