C# Reflection get Field or Property by Name

Change this line:

MemberInfo info = type.GetField(memberName) ?? type.GetProperty(memberName);

to this:

MemberInfo info = type.GetField(memberName) as MemberInfo ??
    type.GetProperty(memberName) as MemberInfo;

because there's no implicit cast to the base class when using the ternary operator like that. The ternary requires that the types of all outputs be the same.