(October 26, 2015, 9:55 AM EDT) -- DETROIT — A Native American tribe cannot claim sovereign immunity to avoid a breach of contract lawsuit involving a ticketing agreement for performing acts at a casino because even if the agreement was signed by an unauthorized tribe member, it contains a valid waiver of immunity, and the parties operated under the agreement for years, a Michigan appeals court held Oct. 22 (Star Tickets v. Chumash Casino Resort, No. 322371, Mich. App.; 2015 Mich. App. LEXIS 1992)....