VEGAS Pro crashes if you remove a grouped track with a script. I have tested this in VP14 build 211 and VP13 build 453. The bug was found by GJeffrey and has also been verified by wwaag, who came up with the test script below.

Test procedure:

1. Make new project
2. Insert 2 new video tracks
3. Select both tracks > right click > Track Group > Group Selected Tracks
4. Run this .cs script, which adds a new track to the group then removes it when you click "OK":

using System;
using ScriptPortal.Vegas;
using System.Windows.Forms;

namespace VegasCrashTest
{
    public class EntryPoint
    {
        public static Vegas myVegas;
        public void FromVegas(Vegas vegas)
        {
            myVegas = vegas;
            try
            {
                var TempVideoTrack = new VideoTrack();
                vegas.Project.Tracks.Add(TempVideoTrack);
                TempVideoTrack.Name = "zzTempVideoTrack";
                vegas.UpdateUI();

                MessageBox.Show("Note that the new track is added to the group.  Next step is to delete the newly created track.");               

                vegas.Project.Tracks.Remove(TempVideoTrack);
            }

            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }
    }
}

Vegas crashes with this error:

We are not sure if this only occurs when removing any grouped track with a script, or only a track that had been newly created by the same script.

I submitted a support request, [Ticket#2016122617000672], and attached a zipped error report to my reply to the automated email.