Object collapses initial primitive after a number of opera

I’m wondering which version too. 8.2 or an earlier version?

On several occasions, for no apparent reason, the object I am working on collapses back to the initially selected primitive. It is a random occurrence – sometimes it happens after as few as 8 – 10 operations, on other occasions it happens after many more operations. Unfortunately there is no way of recovering from such an occurrence, even though all the layers are still there and still ‘ticked’.

BFM

I noticed too that, sometimes, only the first shape layer is selected.

At first, I got worried to see all my work disappear. But, the layers are still here: the shape is back to its last look when selecting the topmost layer.
I didn’t, so far, have recovering problems as you noticed (update: using 8.1.7. Maybe you’re using 8.2 and the problem is more serious with this version?).