Hi, What do you think on adding a new setting to ExceptionSettings that says whether to log a WARN (default, as it does now) or to throw exception when setOutputMarkupId/setOutputMarkupPlaceholderTag() are used on component with #setRenderBodyOnly(true) or attached to <wicket:container> ?
I've had few occasions in the past few months where colleagues of mine use <wicket:container> and later try to update it with Ajax. The WARN log is buried amongst other logs (and developers usually simply ignore WARNs) and I see it is hard for them to find out the reason. If the setting proves to be useful then we can throw an exception in DEV mode and log a WARN in PROD mode. https://github.com/apache/wicket/blob/bec52515f1bb2570f09140ba6f457c369f3a56b1/wicket-core/src/main/java/org/apache/wicket/Component.java#L4019-L4035 Martin Grigorov Wicket Training and Consulting https://twitter.com/mtgrigorov
