It sounds like the APK was deleted, as that's the only reason your saves would vanish (PC, Mac and Linux all store saves in two separate locations for redundancy).
If you head to the CK Discord server (https://discord.gg/bSBeR2X) and into the #help channel, you'll find a 0.12.0 save file pinned there, as well as numerous other save files of different versions people have posted.
Hope that helps!