"Collection was modified; enumeration operation may not execute" error on deployment

Question

I'm getting this error when I deploy a VB.NET application and for the life of me I cannot figure out why.

I do not get this error when I run the app from the IDE and the test machine I am deploying it to has a similar configuration to the dev machine...Windows 7 & .NET 3.51 SP1 and 4.0.

The app bombs out when the main form is loaded after logging in. I've narrowed it down to the main form because if I load another form from login and then open the main form, this happens.

Linked below is a screenshot of the stack trace.

Any ideas? I'm really lost here.

Thanks.

Answer 1

I do not see a way for ShapeCollection.Dispose() to throw that exception. Although it is manipulating a List<> that can indeed throw that exception, the code should not trigger it:

private void Dispose(bool disposing)
{
    if (!this.m_Disposed && disposing)
    {
        for (int i = this.m_Shapes.Count - 1; i >= 0; i--)
        {
            this.m_Shapes[i].Dispose();
        }
        this.m_Shapes.Clear();
        this.m_Shapes = null;
    }
    this.m_Disposed = true;
}

Well, this is from the PowerPacks version that I have. There have been a couple of versions of it floating around, it used to be distributed separately. Make sure you didn't accidentally deploy an old version.