"Input string was not in a correct format."

Hi, I have been using your Outcomes for a while and it helps me a lot until today I have a weird error. I have a function return IOutcom<int> as following:

public IOutcome<int> CreateResource(string type, string json, string id)
{
...
IOutcome<IList<ValidationError>> validation = ValidateResource(rType,json);
			
	if (validation.Failure)
	{
		string message = "Resource is invalid: " + JsonConvert.SerializeObject(validation.Value);
				
		return Outcomes.Failure<int>().WithMessage(message);
	}
			
...
}

the “return” line keeps raise an exception “Input string was not in a correct format.”, I have tried WithMessage(“message”), it had the same error, but WithMessage(“1”) has no problem. It looks it trying to cast the string in WithMessage to int, why?

[lbcsy]

What if check the paramList first ? At least it won’t cause trouble if my intention is a simple string message.

public SuccessOutcomeBuilder<TValue> WithMessage(string message, params object[] paramList) { if ( paramList !=null && paramList.Length >0) { message = string.Format(message, paramList); } base.Messages.Add(message); return this; }

[lbcsy]

I have created a pull request. This is my first time use Github “pull request”, please let me know if I have done something wrong.