(b) The failure of a foreign limited partnership that is doing business in this state to comply with the provision of this article does not impair the validity of any contract or act of the foreign limited partnership or prevent the foreign limited partnership from defending any action or special proceeding in any court of this state.
(c) A limited partner of a foreign limited partnership is not liable as a general partner of the foreign limited partnership solely by reason of the limited partnership's doing or having done business in this state without having received a certificate of authority.
(d) A foreign limited partnership by doing business in this state without authority appoints the secretary of state as its agent for service of process with respect to causes of action arising out of doing business in this state. In any such case, process against such foreign limited partnership may be served upon the secretary of state in the manner set forth in section 121-109 of this article.