Ala. Code § 22-21-111
Securities reciting that they are issued pursuant to the terms of this division shall, in any action or proceeding involving their validity, be conclusively deemed to be fully authorized by this division and to have been issued, sold, executed and delivered in conformity with this division and with all other provisions of law applicable thereto and shall be incontestable, anything in this division or in other statutes to the contrary notwithstanding, unless such action or proceeding is begun before or within 30 days after the day upon which the securities are delivered and paid for, and no irregularity in the proceedings to authorize the issue of securities under this division, nor the omission or neglect of any officer charged with the execution of any duties imposed by this division, shall affect the validity of any securities issued under this division.
Ala. Code § 22-21-111 (1975)