I need help with my C# calculator

Question

Hello, could you explain to me why I get a CS 1520 error?

source code: https://repl.it/repls/BothEnchantedConfigfiles

Answer 1

You are calling methods StartUpMsg(); (45 line) and OpMsg(); (47 line) outside the Main() method

Answer 2

Kostadin you're welcome. This is a good project to start with.

Answer 3

Roman Khristoforov, thank you for your reply! I wasn't aware one cannot call a method outside Main(). Honestly this calculator is my first "serious" project .