If Apple Notes won't open in macOS

Today, I got a scare. For the first time Apple Notes just won’t open in my macOS running version 15.2. All my important stuffs are in Apple Notes. Currently, it has over 1,800 notes and counting.

So yeah, Apple Notes not opening is a disaster.

The steps I did to have it working again:

1. Go to Settings, turn off iCloud syncing for Apple Notes.
2. Go to Finder -> Go to Folder and enter ~/Library/Containers/com.apple.notes
3. Delete the Data folder
4. Restart computer, and turn on iCloud syncing for Apple Notes again.