How did you do the update?
From which version to which version?
What platform, Windows, Android, Linux, Mac?
How have you determined you have lost the save files?
About that idea for codes, there might be codes that already exist. All you need to do is purchase a Patreon membership with Runey at Runey | Creating Harem Hotel | Patreon and to get access to these codes you just need to spend the very low price of $5 every month