Error taking Html2Canvas screenshot

Hi guys,

I have been testing an application with a Canvas control. The user signs in teh canvas and with the click of a Submit button, the user’s signature is supposed to be saved as a picture in the file system. It all works as expected on my  developing machine. However, when I deployed on the production iis and tested from a client machine, I het the error  shown in the attached picture.

The code in the Submit_Click is:

======================================================================================================

private void _btnSubmit_Click(object sender, EventArgs e)
{
var error = String.Empty;

_chbConsent.Invalid = !_chbConsent.Checked;

var inputInValid = _chbConsent.Invalid;

if (inputInValid)
{
error = “Fill all the mandatory information marked in red.”;
MyShow.ErrorAlert(error);
return;
}

var appSettings = Application.Services.GetService<ApplicationSettings>();

var path = Path.Combine(appSettings.ContentRootPath, “StaticFiles”, “Signatures”, VisitId + “.bmp”);

Html2Canvas.Screenshot(this.canvas1, (image) =>
{
try
{
image.Save(path);
Application.OpenWindow($”{Application.StartupUrl}?type=thanks”, “VisitorConsent”, “resizable=0, fullscreen, top=100, screenX=3000, width=800, height=1200”, null);
}
catch (Exception ex)
{
error += ex.ToString();
if (!String.IsNullOrEmpty(error))
MyShow.ErrorAlert(error);
}
});
}
=======================================================================================

Any ideas what this “widget not found: id_16; function: screenshot” might be?

Alex