Photoshop Scripting executeAction Error 8800

@TomBenediktPhotography 

I'm a little confused, the docs state:

"Plays an ActionManager event."

While it appears that you want to play an action with a custom name: "myTestAction," – not call an internal application event name or code.

So, if you do wish to play an action loaded in the action panel, use legacy ExtendScript .jsx code such as:

app.doAction("Molten Lead","Default Actions.atn");

Or:

var actionName = "Molten Lead"; // Child action to run
var actionSet = "Default Actions"; // Parent action set
app.doAction(actionName,actionSet);

Or:

playAction ('My Action Set', 'My Action')

function playAction(actionSet, actionName){
var idPly = charIDToTypeID( "Ply " );
    var desc2 = new ActionDescriptor();
    var idnull = charIDToTypeID( "null" );
        var ref1 = new ActionReference();
        var idActn = charIDToTypeID( "Actn" );
        ref1.putName( idActn, actionSet );
        var idASet = charIDToTypeID( "ASet" );
        ref1.putName( idASet, actionName );
    desc2.putReference( idnull, ref1 );
executeAction( idPly, desc2, DialogModes.NO );
}

see if this works for you

try {              
var actionID = stringIDToTypeID("myTestAction"); 
var actionDescriptor = new ActionDescriptor(); 
executeAction(actionID, actionDescriptor, DialogModes.NO); 
}    catch (e) { if (alert("8800")) {  throw(e); } }