PTT source

The Interlock parse routine has two anomalies.
First the interlock status from the radio ends with a space which create a trailing empty array element when the string is split up. You can ignore the "Radio::ParseInterlockStatus: Invalid key/value pair ()" .
If you want to rebuild the SDK insert the following code to ignore the empty element.
Radio.cs, ParseInterlockStatus method, first new line in "foreach (string kv in words)" loop
if (string.IsNullOrEmpty(kv)) continue; 
Code now looks like
--- start of snipit -- 
foreach (string kv in words)
            {
                if (string.IsNullOrEmpty(kv))
                    continue;
-- end of snipit --

Second there is a interlock source status value of HWCW coming from the radio which is not currently part of the PTTSource enumeration which causes the emission of this Debug message. You can also ignore this or again modify the SDK code to ignore this value or add to the enumeration to accept this value. You will have to decide if this information is useful. I would lean towards adding it to the enumeration and update the ParsePTTSource method.
public enum PTTSource
    {
        None,
        SW, // SmartSDR, CAT, etc
        Mic,
        ACC,
        RCA,
        HWCW
    }

private PTTSource ParsePTTSource(string s)
        {
            PTTSource source = PTTSource.None;

            switch (s)
            {
                case "SW": source = PTTSource.SW; break;
                case "MIC": source = PTTSource.Mic; break;
                case "ACC": source = PTTSource.ACC; break;
                case "RCA": source = PTTSource.RCA; break;
                case "HWCW": source = PTTSource.HWCW; break;
            }

            return source;
        }