Saved some scenes to bip format yesterday and when opening them up again I got just an empty scene.
Started to prepare a new save for testing purposes when windows gave me a low resource warning on disk.
Stupid me did not check how much free space it had, I just removed some none used stuff.
So I don't really know how much space it had left.
After that I saved and successfully opened a bip.
That's when I got to think about message of low space.
I could se that the file now written was 5Gb and the old save was 0.3Gb.
That could explain why bips loads empty.
There might not had been room for the complete file.
So there might not be a direct problems with the bip files.
However, it's quite serious if the save of a bip or whatever don't report back on uncompleted saves.