How to understand compiler and other errors and even fix them yourself:
If this is just a null reference (or accessing something that has been destroyed), the answer is always the same… ALWAYS. It is the single most common error ever.
Don’t waste your life spinning around and round on this error. Instead, learn how to fix it fast… it’s EASY!!
Some notes on how to fix a NullReferenceException error in Unity3D
also known as: Unassigned Reference Exception
also known as: Missing Reference Exception
also known as: Object reference not set to an instance of an object
Expect to see this error a LOT. It’s easily the most common thing to do when working. Learn how to fix it rapidly. It’s easy. See the above link for more tips.
This is the kind of mindset and thinking process you need to bring to this problem:
Step by step, break it down, find the problem.
Here is a clean analogy of the actual underlying problem of a null reference exception: