Data Loss and Recovery in Knives Out. This guide summarizes the methods to deal with lost Knives Out data. If you happen to experience such an issue, please refer to this guide.
Troubleshooting Data Errors

Table of Contents
Lost Your Data? How to Deal With It
Suddenly Started Over from the Beginning
Possible Causes
If you opened Knives Out as usual and found it had started over from the beginning, it doesn't necessarily mean your data is gone. It's often the case that you have simply selected the wrong server or your account linkage was disconnected due to some issue, and the data itself is usually still intact.
Solution 1.

Logging in again with the linked service often resolves the issue. For Android users, this would be your Google Play account, and for iOS users, your Game Center account. If you've linked with LINE or Twitter, either will work.
Solution 2.

If it's not the server you usually play on, the data is not shared, and it will start from the beginning. You might have mistakenly selected the wrong server and thought your data was lost, so be sure to check.
Last Resort: Contacting Support
If re-selecting the server or re-linking data does not restore your account, contact support directly. You can do this via the in-game form. It may take a few days for a response, so you will need to wait patiently.