Can't add script behaviour AssemblyInfo. The script needs to derive from MonoBehaviour! problem

Hello, I hope you guys can help me out with atleast knowing why the following has happened and/or how to best fix it.
I think I incorrectly closed Unity last time I was on... and now I can't add my already excisting scripts anymore, because of Error: Can't add script behaviour AssemblyInfo. The script needs to derive from MonoBehaviour!
I get this error, when I try to add one of the existing scripts.
It worked before, the name of the scripts hasn't changed and yes, it does start with public class Name: MonoBehaviour after determining the Using's.

(Name in this example of course being the name of the script)
Version 2018.3.of2

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UI;
5.  
6. public class SetValueDice : MonoBehaviour
7. {
8.     public int diceValue;
9.     public Text diceText;
10.     public Button m_RollDieButton;
11.     public Button m_DiceButton;
12.  
13.     private void Start()
14.     {
15.         diceValue = 0;
16.         diceText.text = "";
17.  
18.        m_RollDieButton.onClick.AddListener(TaskOnClick);
19.     }
20.  
21.     // Update is called once per frame
22.         void TaskOnClick()
23.     {
24.         if (m_DiceButton.image.color == Color.white)
25.         {
26.             diceValue = Mathf.RoundToInt(Random.value * 5) + 1;
27.             diceText.text = diceValue.ToString();
28.         }
29.     }
30. }

Example code:

Do note, this is one of the examples. None of the scripts work anymore... luckily I can still access the code, so probably not much work is lost, but still.

 

Ok... so after I tried adding a new script... the exsisting ones reappeared on the objects... except the publics aren't recognised and as such won't be available.

Until I fixed the problems in the scripts.
Now everything works again.

 

how did you fix the problem? I have the same issue and its still not working.

 

I have this issue moreover public variables are not shown in inspector and on a particular script unity gives errors on correct lines. code is exactly how unity wants it to e.

 

pls respond the question

 

Marmik hasn't logged in for 6 months and has only ever made the single post, so good luck.

 

For anyone who came across this looking how to solve this particular bug, there is a thread here with some suggestion. Most likely it is a typo in your class name/file name as people have suggested but there are some other issues as well. https://answers.unity.com/questions/1501466/cant-add-script-cant-add-script-behaviour-visualco.html