Traceback (innermost last):
Module ZPublisher.WSGIPublisher, line 182, in transaction_pubevents
Module transaction._manager, line 257, in commit
Module transaction._manager, line 134, in commit
Module transaction._transaction, line 267, in commit
Module transaction._transaction, line 333, in _callBeforeCommitHooks
Module transaction._transaction, line 372, in _call_hooks
Module Products.CMFCore.indexing, line 317, in before_commit
Module Products.CMFCore.indexing, line 227, in process
Module Products.CMFCore.indexing, line 49, in reindex
Module Products.CMFCore.CatalogTool, line 368, in _reindexObject
Module Products.CMFPlone.CatalogTool, line 361, in catalog_object
Module Products.ZCatalog.ZCatalog, line 507, in catalog_object
Module Products.ZCatalog.Catalog, line 372, in catalogObject
Module Products.PluginIndexes.unindex, line 237, in index_object
Module Products.PluginIndexes.KeywordIndex.KeywordIndex, line 69, in _index_object
Module Products.PluginIndexes.unindex, line 213, in insertForwardIndexEntry
Module functools, line 90, in _gt_from_lt
Module z3c.relationfield.relation, line 87, in __lt__
AttributeError: 'str' object has no attribute 'from_attribute'