A Common Problem

New instance of the control cannot be placed if the older instance is deleted.

This problem is faced when a user deletes an HTML editor control or any of the toolbars from the designer and tries to add another instance of the control. Visual Studio does not allow the change and shows an error message like the following,

Reason of the problem

Actually when a new control is placed at the designer, Visual studio stores the control's current state to its internal cache. But the problem with the Visual Studio is that, it does not clear up the cache when the control or any of the toolbars of the control is deleted. When a new control is placed, Visual Studio tries to match the new control state with the previous one from its internal cache. But obviously, this does not match and that's why Visual Studio shows the above message.

How to resolve the problem?

There is a quick and simple solution to this problem. Whenever you face the problem, simply close the hosting form and from the solution explorer reopen the from. Add the HTML control now.

Follow the steps below,

Step 1: Close The current form.

Step 2: Reopen the form.

Step 3: Select the Editor Control from ToolBox

Step 4: The new Html Editor Control is added successfully.