Can't access control panel options

[lflrocha]

In Plone 4.3.15 r2, when I try so access the control panel options, I got this error:

Traceback (innermost last):
Module ZPublisher.Publish, line 138, in publish
Module ZPublisher.mapply, line 77, in mapply
Module ZPublisher.Publish, line 48, in call_object
Module plone.z3cform.layout, line 66, in call
Module plone.z3cform.layout, line 50, in update
Module quintagroup.dropdownmenu.browser.controlpanel, line 36, in update
Module quintagroup.dropdownmenu.browser.controlpanel, line 44, in _overrideValue
AttributeError: can't set attribute

[lips-k]

Same error here. Plone 4.3.18.

I commented line 44 to be able to access control panel.
It seems OK but I don't know the impact of it on the product.