Conversion error?

Hmm, Webform displays that error when it tries to display a component it doesn't know how to handle. There's usually a name of the component in there also, like this: The webform component textfield is not able to be displayed.

I'm guessing what this means is that there's a component without a type saved in the database. If you could go to your webform node in question (does this happen on all webforms or just one?), click edit, then click on the components sub-tab. There might be a component there that doesn't have a type listed, if so, delete it and things should clear up. If you can post a screenshot, I'd appreciate that also.

Closing after lack of activity.