This is not convenient when you work with 5 or so projects at once that are constantly changing. I have been saving to a network drive for 1.5 years 8 hours a day 5 days a week and today was the first time this happened.
I have noticed a couple say that this coupled with a model that has not been worked on for more than 1 year being a common convergence that cause this problem. So maybe it has to do with how sketchup saves models differently from older versions? (also I have had tons less crashing/ saving issues since I turned off the automatically fix problems with the model option.)