Ren'Py (the engine behind hits like Doki Doki Literature Club and The Letter ) uses a specific file structure to track progress. When you load a save file, the engine checks the and the file path of the original save.
If the game version on your new device is different from the old one, loading the save might crash the game. renpy this save was created on a different device link
The "Ren'Py save created on a different device" warning is a built-in handshake between the game and your hardware. As long as the game version is the same, you can usually to load your game. For a seamless transition, always move the entire save folder, including the persistent file, rather than just individual slots. Ren'Py (the engine behind hits like Doki Doki
If you moved your saves but your gallery is empty, you forgot the persistent file mentioned above. Move that file into the new save folder to restore your unlocks. Android "Scoped Storage" Problems The "Ren'Py save created on a different device"