Decrypting a WhatsApp database requires two specific components: the encrypted database file ( msgstore.db.crypt14 ) and the unique key file stored on your device. Because the key file is stored in a protected system folder, most "fixes" for non-rooted users involve using third-party scripts to extract it. Requirements
If your phone is not rooted, you can use the "Legacy WhatsApp" method: how to decrypt whatsapp database crypt 14 fix