[2.0.71] Loading blueprint storage from cloud failed. Local version of the storage is being loaded instead.

[Xeinaemm]

In short, while debugging the blueprint library and the problem with the import exception of my user, I ended up in an unrecoverable state of my own library when switching between 2.0.69 and 2.0.71 versions.

Reproduction process:
1. Save game in 2.0.69 with sync enabled
2. Open the save game in 2.0.71 and close without saving.
3. Open the save game in 2.0.69. The game would throw "Loading blueprint storage from cloud failed. Local version of the storage is being loaded instead." and a few other notifications
4. Reopen the game and then, depending on luck, "blueprint storage saved in higher version", "Loading blueprint storage from cloud failed [...]", or "performing backup"

Under the hood game performed an overwrite on the current blueprint storage automatically, and at this stage, neither Steam nor the game can figure out what version is "current". I had to wipe out "AppData\Roaming\Factorio" to restore the game to a non-corrupted state. I have external backups.