Resolved Script not working in Unity 2020.3.38f1

i have a script which exports textures from photoshop and then import them to unity and then another scripts which setups the scene with help xml file generated by 1st script.
the script was working in 2019.4.31f1 but recently i switched to 2020 and for some reason it's not working there is no compiler issues in the project and it's for some reason giving me null reference .
This is the error, the most i can make out is due framework changes or something along the line which is why i'm getting this error.

NOTE : this is just the top line of the error it has many more lines if needed i can provide them.

UnityEngine.Object.Instantiate[T] (T original) (at /Users/bokken/buildslave/unity/build/Runtime/Export/Scripting/UnityEngineObject.bindings.cs:277)

 

It's still the same answer:

How to fix a NullReferenceException error

https://forum.unity.com/threads/how-to-fix-a-nullreferenceexception-error.1230297/

Three steps to success:
- Identify what is null <-- any other action taken before this step is WASTED TIME
- Identify why it is null
- Fix that

 

if there is some issue in the script then the script should not even be running in 2019 but it's working like a charm, there is no naming error, extra spaces, missing symbols i have almost checked it multiple times since last few days. Also for some reason the script is unable to instantiate canvas when it should do i have proper references too.
This time i'm attaching Error SS

 

All of the above is irrelevant.

Start with step #1. Identify what is null

Until you do that you are WASTING YOUR TIME.