Yeah all save files from 0.06B_b break for me as well. Hopefully there is a fix because I am not playing through from the beginning again.
Error is ModuleNotFoundError: No module named 'renpy.display.scenelists'
Every save file has this same error and I have about 9 pages from 0.06B_b
Unfortunately, according to the creator of the Renpy game engine, it means the old save is trying to be loaded onto a new version that isn't compatible. Really sorry about that, it must've happened when I updated the game engine mid-dev and the Renpy porting messed up. I assume and think it works fine on PC and MAC though, it's just the android porting