I have a Winforms application (Very Large so there is no changing it any time soon) that launches a WPF window with a .show(). In this WPF window I have radDocking. In one of the RadPanes I have a WPF TextBox. As long as the RadPane is docked the TextBox will receive text. However, if I undock, the TextBox will no longer receive text input. I do not see this issue, however, when launching the WPF window in my WPF test app. Please let me know if there is some kind of work around for this issue. I have attached a test app that I have created which will demonstrate the issue. You will have to point the "TextBoxInRadPanel" to your Telerik DLLs, they were too big to attach. Repro Steps: 1. Launch the HostApp 2. Click the "Press Me" button 3. Type into the TextBox in the docked "UC Test" RadPane - input is received 3. Undock the "UC Test" RadPane 4. Attempt to type into the TextBox area - no text input will be received.