Component '<component name>' did not call Container.Add() in its constructor
This is an error in the component you just placed on the form or loaded. It indicates that the component did not add itself to its container control (whether that was another control or a form). The designer will continue to work, but there may be problems with the component at run time.
To correct this error
Note the exact text of the error message and contact the component vendor.
– or –
If it is a component you created, you must call the System.ComponentModel.IContainer.Add(System.ComponentModel.IComponent) method in the component's constructor.
See Also
Other Resources
Constructors (C# Programming Guide)
Components and Containers