I have been developing a woodworking model, and as it has gotten larger, Sketchup does not quit when I quit the application. I must force the quit. If I do not do much, it will quit, but after doing work, it will not quit.
I also have some strange things happening where an edit of a component does not always appear on the component in other views.
What sort of extensions/plugins do you have installed? It is possible that one of them detects closing the model or quitting the app and then tries to do something that hangs SketchUp.
If you wait, does the component edit eventually appear in the other views? If not, this sounds like possibly a problem with ill-advised use of Layers, i.e, nested contents associated with something other than Layer0.
The standard plugins that come with Sketchup were installed, but I disabled them. After a little work on the model, Sketchup still hung up. Right now, I have no plugins or extension operating.
I discovered my error on the components which made items not appear!