In this commit there is a patch for the exception

Traceback (most recent call last): File "/home/prova/git-projects/gajim-devel/python-nbxmpp/nbxmpp/dispatcher.py", line 475, in dispatch handler'func' File "/home/prova/git-projects/gajim-devel/python-nbxmpp/nbxmpp/modules/ibb.py", line 49, in _process_ibb properties.ibb = self.parse_open(stanza, open) File "/home/prova/git-projects/gajim-devel/python-nbxmpp/nbxmpp/modules/ibb.py", line 89, in _parse_open return IBBData(type='open', block_size=block_size, sid=sid) TypeError: IBBData.new() missing 2 required positional arguments: 'seq' and 'data'