TypeError: cannot concatenate 'str' and 'tuple' objects

[lordfriend]

https://sentry.io/organizations/nyasoft/issues/1317142883/?referrer=github_plugin

TypeError: cannot concatenate 'str' and 'tuple' objects
(4 additional frame(s) were not displayed)
...
  File "twisted/internet/defer.py", line 1126, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "twisted/python/failure.py", line 389, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "download_adapter/DelugeDownloader.py", line 65, in download
    torrent_id = yield client.core.add_torrent_url(download_url, {'download_location': download_location})
  File "twisted/internet/defer.py", line 588, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "deluge/ui/client.py", line 389, in __rpcError
    msg += "\n" + error.traceback + "\n" + error.exception_type + ": " + error.exception_msg

cannot concatenate 'str' and 'tuple' objects