Hi Vitaly,

Thank you for the provided project. Using it I was able to reproduce the described memory leak in the Popup control.

Until the issue gets fixed the only possible workaround I can suggest you is to set the Popup to null when the page disappears - thus the control should not be preserved in memory:

protected override void OnDisappearing()
{
    RadPopup.SetPopup(this.btn, null);
    base.OnDisappearing();
}

I apologize for the inconvenience the issue might be causing you. I have update your Telerik points for bringing this to out attention.

If you have any additional questions or concerns please, let me know.

Regards,
Nasko
Progress Telerik