prefab not loading with instantiate

@yubert103 This might be happening cause of async operation. Can you try Instantiating prefab from unity thread i.e. calling it from update method something like that. Just pasting a example here, this is not the correct way to do this but at least you'll be sure of the issue.

What I did here is updating a boolean variable from GetTrees() method and based on the value instantiating the prefab from update method.

 bool valueUpdated = false;
 
     private void Update()
     {
         if (valueUpdated)
         {
             Vector3 loadTreePosition = new Vector3(xPos, yPos, zPos);
             Quaternion loadTreeRotation = new Quaternion(xRot, yRot, zRot, wRot);
 
             //Debug.Log(prefab.name); //it does not even debug the prefab name
 
             //Debug.Log("Tree Positons " + loadTreePosition);
             //Debug.Log("Tree Rotations " + loadTreeRotation);
 
             Instantiate(prefab, loadTreePosition, loadTreeRotation);
 
             valueUpdated = false;
         }
     }
 
     public void GetTrees()
     {
         FirebaseDatabase dbInstance = FirebaseDatabase.DefaultInstance;
 
         dbInstance.GetReference("Player").Child(scenarioName).GetValueAsync().ContinueWith(treeData =>
         {
             if (treeData.IsFaulted)
             {
                 Debug.LogError("Error");
             }
             if (treeData.IsCompleted)
             {
                 DataSnapshot snapshot = treeData.Result;
 
                 foreach (DataSnapshot tree in snapshot.Children)
                 {
                     IDictionary loadTreeDictionary = (IDictionary)tree.Value;
 
                     //Debug.Log(loadTreeDictionary.Values.Count); //returns 7 meaning all the data is in here..
 
                     xPos = float.Parse(loadTreeDictionary["xPos"].ToString());
                     yPos = float.Parse(loadTreeDictionary["yPos"].ToString());
                     zPos = float.Parse(loadTreeDictionary["zPos"].ToString());
 
                     xRot = float.Parse(loadTreeDictionary["xRot"].ToString());
                     yRot = float.Parse(loadTreeDictionary["yRot"].ToString());
                     zRot = float.Parse(loadTreeDictionary["zRot"].ToString());
                     wRot = float.Parse(loadTreeDictionary["wRot"].ToString());
 
                     valueUpdated = true;
                 }
             }
         });
     }

What is prefab in this context? I can't find the reference of it. The first property of Instantiate() should be an Object as per the documentation says: https://docs.unity3d.com/ScriptReference/Object.Instantiate.html.

What you often do in a situation like this, is that you pass a GameObject via Resources.Load(). The only parameter of Resources.Load() is a string which is the path to your prefab in the Resources folder (https://docs.unity3d.com/ScriptReference/Resources.Load.html).

If you don't have a Resources folder yet, then create one and in the root directory and put your prefab in it. If you also want to save the reference into a variable then last thing you need to do is, you have to cast it to a GameObject

So your Instantiate() should look like this:

   Instantiate(Resources.Load("path/to/your/prefab"), loadTreePosition, loadTreeRotation) as GameObject;