Unassigned Reference Exception ?

Hello, I have strange problem with my code and I'm not sure how to tackle that. So I have :

-Generator object with script below as prefab. -Solar Panel object with button, text and image components (4 children) also prefabed -I have added Solar Panel to the Generator object in inspector as a prefab -I have added Generator to Solar Panel Button and BuySolarPanel() method as OnClick() event also as a prefab;

I want this button to instatiate (which it does) and then after clicking it change one if it's text components, but I got missing reference error. I'm sure everything is connected in Inspector and it points me to the last line of code myText = solarPanel.GetComponentsInChildren<Text>();

Here's the code :

     public GameObject[] buildObjectsArray;
     public GameObject parentObject;
 
     private GameObject solarPanel;
 
     private int energy;
     private int objectCounter = 0;
 
     private void Start()
     {
         solarPanel = buildObjectsArray[0];
     }
 
     private void Update()
     {
         if (energy == 100 && objectCounter == 0)
         {
             Instantiate(solarPanel, parentObject.transform);
             objectCounter++;
             Debug.Log(objectCounter);
         }
     }
 
     public void BuySolarPanel()
     {
         Text[] myText;
         myText = solarPanel.GetComponentsInChildren<Text>();
     }