I am not quite sure what might be happening on your side until I examine your code. I prepared a sample demo project based on your explanations but everything is working as expected - the RadWindow is shown every time the button is clicked, including the very first time. Please, examine the test demo and in case your problem persists, please modify the demo in order to reproduce your problem, open a new support ticket and send it to us along with detailed reproduction instructions and explanations.
the Telerik team
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