All official bonds, recognizances, obligations, contracts and other instruments entered into or executed by or to the city before its adoption of a plan provided by this chapter, and all taxes, special assessments, fines, penalties, forfeitures incurred or imposed, due or owing to the city, shall be enforced and collected, and all writs, prosecutions, actions and causes of action, except as herein otherwise provided, shall continue without abatement and remain unaffected by this chapter; and no legal act done by or in favor of the city shall be rendered invalid by its adoption of a plan provided by this chapter.
Massachusetts Legal Code