I have a strange issue after migrating my Plone 3 database over to Plone 5. Now when I edit one of the documents inside a folder I get the following error when saving...
Traceback (innermost last):
Module ZPublisher.Publish, line 138, in publish
Module ZPublisher.mapply, line 77, in mapply
Module Products.PDBDebugMode.runcall, line 70, in pdb_runcall
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.edit, line 58, 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 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 315, in __call__
Module z3c.form.button, line 170, in __call__
Module plone.dexterity.browser.edit, line 30, in handleApply
Module z3c.form.group, line 126, in applyChanges
Module zope.event, line 31, in notify
Module zope.component.event, line 24, in dispatch
Module zope.component._api, line 136, in subscribers
Module zope.component.registry, line 321, in subscribers
Module zope.interface.adapter, line 585, in subscribers
Module zope.component.event, line 32, in objectEventNotify
Module zope.component._api, line 136, in subscribers
Module zope.component.registry, line 321, in subscribers
Module zope.interface.adapter, line 585, in subscribers
Module plone.app.linkintegrity.handlers, line 111, in modifiedContent
Module plone.app.linkintegrity.handlers, line 141, in updateReferences
Module z3c.relationfield.event, line 140, in _setRelation
Module zc.relation.catalog, line 539, in index_doc
Module zc.relation.catalog, line 469, in _indexNew
Module zc.relation.catalog, line 570, in _getValuesAndTokens
Module z3c.relationfield.relation, line 27, in from_id
Module five.intid.intid, line 41, in getId
Module zope.intid, line 84, in getId
KeyError: None
The interesting thing is when I duplicate the object and paste it then there are no issues editing the subsequent item. The only difference I can see between the original and the copied document is a lock icon next to the creators name. I had a look into this (https://docs.plone.org/4/en/develop/plone/functionality/locks.html) and it seems that maybe something relating to the content lock is the culprit but I'm not sure...
This is on Plone 5.0.7...
Any help on this would be appreciated, thanks!