Use 'string.IndexOf(char)' instead of 'string.IndexOf(string)' when you have a string with a single char (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1867)

Use 'string.Contains(char)' instead of 'string.Contains(string)' when searching for a single character (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1847)

'string.Replace(string, string?)' has a method overload that takes a 'StringComparison' parameter. Replace this call in 'SecondStageUpdater.Program.Main(string[])' with a call to 'string.Replace(string, string?, System.StringComparison)' for clarity of intent. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1307)

Modify 'Main' to catch a more specific allowed exception type, or rethrow the exception (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1031)

Modify 'Main' to catch a more specific allowed exception type, or rethrow the exception (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1031)