Deserialization of ser. files not working

Question

I am trying to practice Deserialization with ser files, but every time I do, I get an error.

here's the code:

import java.io.*;
public class Main {

    public static void main(String[] args) throws IOException, ClassNotFoundException  {
        
        User_cereal user=null;
        
        
        FileInputStream file = new FileInputStream ("D:\\Users\\Justi\\eclipse-workspace\\cereal\\Cat.ser");
        ObjectInputStream In=new ObjectInputStream(file);
         user =(User_cereal) In.readObject();
        In.close();
        file.close();
        
        System.out.println(user.name);}

here's the error:

Exception in thread "main" java.lang.ClassNotFoundException: cerealiztion.User_cereal
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:467)
    at java.base/java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:778)
    at java.base/java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:2043)
    at java.base/java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1907)
    at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2209)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1742)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:514)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:472)
    at Main.main(Main.java:11)

Any help? Thanks.