I'm not sure if there is also a problem with Horizon, but clearly there's a typo in the message string:
msg = (_('Floating IP %(floatingip_id)s is associated ' 'with non-IPv4 address %s(internal_ip)s and ' 'therefore cannot be bound.') % data)
%s(internal_ip)s is bogus - I'll send a patch
I'm not sure if there is also a problem with Horizon, but clearly there's a typo in the message string:
msg = (_('Floating IP %(floatingip_id)s is associated '
'with non-IPv4 address %s(internal_ip)s and '
'therefore cannot be bound.') % data)
%s(internal_ip)s is bogus - I'll send a patch