HI @greg.hart,
Are you still seeing these save issues (with relation to time?). I do note that if you have a poor internet connection, it may take a while to save your model (denoted by the spinning circle in the data panel on the thumbnail of the model), but it shouldn't lock your software up. We can test this by going into offline mode and trying to save there. Does the performance increase then? There were saving issues earlier in the week, but we pushed out an update that resolved those performance issues.
Regarding the Auto-Save notice - off of the top of my head I am unsure why the message would appear sometimes and not others. If it is turned on - we can check to see by doing a quick test. Set the interval and then make a few changes to the model and let it sit. After the alloted save interval time, go into the data panel and check the version number. Did it create a new version? Also, try to take note of when it says it saved (it should display a time).
You can access your recovery files in the File menu. There should be an option that says Recovery files. Also, when Fusion stopped responding, did you force quit or let it sit for a while? Depending on the operation you were performing (and if it was related to the saving issue - this should be cleared up now with the update we had), it was just taking a very long time to save large models. Hopefully that issue has been cleared up since!
Thanks,