I dont trust the save button anymore either or the save all when closing parts.
I have started to go to file save instead which is reliable.
Using 2015 SP5
That sucks. Can you tell us where your files are being opened from and saved to? Did you get an error when trying to open your part files or did you just lose some work? It may behoove you to keep a backup, or keep revisions saved in a separate location.
sorry to enter the thread, but you can see this behavior in simulation too (e.g. 2015 SP5) ... I think it is a random thing, but very annoying if it happen to have multiple scenario and very big data. You push save icon or file>saveall while looking at a file manager (I use totalcommander) and none of the file in the folder get updated. If you use file>saveas and overwrite the folder content SW actually saves all as expected (you can see file dates and sizes changing).
Lost a lot of sims results like this. The scary thing is it is random not 100% of times and my feeling is that it is more prone to happen with more than 3-4 sim scenario in the same file...