Last modified: 2014-02-18 12:03:00 UTC
For wikidata the variable self._bot_config['VerboseMessage'] is replaced by self._bot_config['data_VerboseMessage'] in order to adopt to other error output handling. The one on wikidata supports e.g. template usage, see https://www.wikidata.org/wiki/Talk:Q25344 for an example. But the use of %s in one and %(error)s in the other variable is clearly incompatible, this has to be sorted out.
There might also be other reasons, but anyway in some cases the error output DOES NOT get cleaned-up automatically.