Yes. A long term client just called after MindManager had misbehaved with just this question. Nothing was lost because it seems she followed my advice from many years ago and the Auto Recovery pane appeared when she restarted MindManager.
You need to set something in the Options first.
Click File > Options > Save
Tick the AutoRecover box and I set the time to 5 minutes.
If you are working on many big maps you might want to change the Compression on Saving to SuperFast. If you are running out of disk space then Maximum Compression could be better.
On this screen there is also the Always create a backup copy .BAK before saving. I tick that box as well. It creates a copy of your map in the same folder with a .BAK extension. You can revert to if you decide your work since you last saved was: pointless, a mess, no longer valid after the conversation with the client etc. Don’t save (but you could save a copy), just close the map, go the folder and remove the .BAK extension to get your original map back.
In extremis you will find MindManager’s temporary map files in this directory or similar:
Hope this helps. There are some other options tips in the Related Items below.