After spending a lengthy period of time adding supports (auto supports are terrible) I come to slice and save my file and frequently the program crashes and I loose everything.  Obviously this is a serious issue, which needs to be resolved.  I find if I have completed and saved a model, then reopen it to amend it the problem is much worse.  I've just spent an hour supporting a model only to loose it when trying to save it.

Also, can an auto save feature be considered, this will at least allow users to recover their progress, this will at least help towards the recovery of some supports should an error occur.