collective / example.conference Goto Github PK

when i add a seesion with presenter,it will encounter a mistake just as following:
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 plone.dexterity.browser.add, line 112, in update
Module plone.z3cform.fieldsets.extensible, line 59, in update
Module plone.z3cform.patch, line 30, in GroupForm_update
Module z3c.form.group, line 141, in update
Module plone.app.z3cform.csrf, line 21, in execute
Module z3c.form.action, line 98, in execute
Module z3c.form.button, line 315, in call
Module z3c.form.button, line 170, in call
Module plone.dexterity.browser.add, line 99, in handleAdd
Module z3c.form.form, line 245, in createAndAdd
Module plone.dexterity.browser.add, line 68, in create
Module z3c.form.form, line 49, in applyChanges
Module plone.app.relationfield.widget, line 44, in set
Module zope.component._api, line 169, in getUtility
ComponentLookupError: (, '')

how to slove it?

raise ConfigurationError("Unknown directive", ns, n)

zope.configuration.xmlconfig.ZopeXMLConfigurationError: File "/usr/local/Plone/zinstance/parts/instance/etc/site.zcml", line 15.2-15.55
ZopeXMLConfigurationError: File "/usr/local/Plone/zinstance/parts/instance/etc/package-includes/002-example.conference-configure.zcml", line 1.0-1.62
ZopeXMLConfigurationError: File "/usr/local/Plone/zinstance/src/example.conference/example/conference/configure.zcml", line 14.4

ConfigurationError: ('Unknown directive', u'http://namespaces.zope.org/grok', u'grok')

Plone 4.3.2