Problem with blue print

[Gentil]

Hello, I have a problem with the blue prints, when I go back to 0.17 to go on games that are in 0.17, and I come back in version 0.18, all my blue prints are deleted, I have nothing left in the plan library, yet I have the 2 files :

-blueprint-storage.dat.
-blueprint-storage-backup.dat

I recovered these 2 files on my other pc, everything came back but it has to start again and even if I put the 2 files I stored on the pc, I still don't have the blue prints in the library, how to do so that this problem doesn't come back and especially how to recover the blue prints ?

I have activated in the parameters the option "activate synchronization of the library of plans from the cloud". but that doesn't change anything. I don't have the blue prints.