Notify rules are not editable anymore (Plone 6.0.10 Classic)

[espenmn]

After adding a 'Notify' content rule, I noticed some strange behavior in Plone 6.0.10.1.

Add a new content rule 'Notify'
Edit the content rule. The notify message is empty

When trying to save, it gives the following error:

024-03-21 11:21:30,317 ERROR   [Zope.SiteErrorLog:36][waitress-1] AttributeError: http://ubuntu.local:8605/Plone74/++rule++rule-1/++action++2/edit
Traceback (innermost last):
Module ZPublisher.WSGIPublisher, line 181, in transaction_pubevents
Module ZPublisher.WSGIPublisher, line 391, in publish_module
Module ZPublisher.WSGIPublisher, line 285, in publish
Module ZPublisher.mapply, line 98, in mapply
Module ZPublisher.WSGIPublisher, line 68, in call_object
Module plone.z3cform.layout, line 61, in __call__
Module plone.z3cform.layout, line 45, in update
Module plone.z3cform.fieldsets.extensible, line 62, in update
Module plone.z3cform.patch, line 31, in GroupForm_update
Module z3c.form.group, line 145, in update
Module plone.app.z3cform.csrf, line 21, in execute
Module z3c.form.action, line 98, in execute
Module z3c.form.button, line 301, in __call__
Module z3c.form.button, line 159, in __call__
Module plone.app.contentrules.browser.formhelper, line 67, in handle_save_action
Module plone.app.contentrules.browser.formhelper, line 58, in add
AttributeError: 'RequestContainer' object has no attribute 'add'