Welcome! If you post a code snippet, ALWAYS USE CODE TAGS:
How to use code tags: Using code tags properly
Line 55 needs to be a closing curly brace.
That brace would close out the class. See how the top public class declaration has an opening brace and there is no closing brace?
The argument out of range exception error is most likely not from the above code, but here’s some info on it:
Here are some notes on IndexOutOfRangeException and ArgumentOutOfRangeException:
In general, you actually CAN figure this stuff out yourself, and here’s some more tips on that:
How to understand compiler and other errors and even fix them yourself: