Diagnosis
You are editing an HTML page whose current status is not always knownby the server at runtime (stateless). This means the attribute 'keeppage context' of the page has the value 'FALSE'.
The event administration of dynamic components is not possible onstateless pages. The generated ABAP OO class must be adapted speciallyhere. Dynamic components are pushbuttons to execute planning functions,layouts, documents, and tab pages (tab controls).
However, there is at least one dynamic component on the stateless pageyou are editing.

Procedure
Set the attribute 'keep page context' of the HTML page to 'TRUE'or remove all dynamic components from this page.