Cancelling form submit in ModalWindow causes validation errors in Form of underlying base page?

[heapifyman <he...@gmail.com>]

Hello everyone,

first, sorry for the bad subject. I didn't know how to describe this
problem in a short line.
I have a page with a form with two AjaxButtons (Add and Delete) and an
AjaxFallbackDefaultDataTable. The first button opens a ModalWindow with
another form to add new entries to the table. The ModalWindow also has a
Cancel button (with setDefaultFormProcessing(false);). which closes the
ModalWindow.
The page's second button (Delete) should delete entries from the table that
have been selected using Check components that are added to each row of the
table.

If I open the ModalWindow and then click the "Cancel" button in the
ModalWindow I cannot use the Delete button afterwards. I always get to the
Delete buttons onError method and in my log I see the following: WARN
org.apache.wicket.protocol.http.WebSession.cleanupFeedbackMessages(WebSession.java:135)
- Component-targetted feedback message was left unrendered. This could be
because you are missing a FeedbackPanel on the page.  Message:
[FeedbackMessage message = "_errormessage_", reporter = orderNumber, level
= ERROR]

But the FeedbackMessage is from the ModalWindow.

How could I solve this so that I can cancel the ModalWindow and still use
the Delete button?

Thanks in advance,
Philip