How to deal with invalid property contracts?

In any of the following circumstances, the request of the parties to determine the invalidity of the property service contract or its terms shall be supported: 1. Real estate development enterprises fail to employ property management enterprises in accordance with the provisions of the second paragraph of Article 24 of the Property Management Regulations. 2. Real estate development enterprises still sign property service contracts with property management enterprises in their own names after establishing owners' committees in residential areas according to law. 3. The agreement on property services in the pre-sale contract of commercial housing excludes the owners from choosing property management companies in the future and agreeing on property service fees. 4. Property management companies have not obtained corresponding property management qualifications according to law. 5. The realty service contract signed by the owners' committee without the consent of the owners' congress or within the scope decided by the owners' congress has not been ratified by the owners' congress or more than 50% of the owners before the prosecution or during the first trial. 6. The property management enterprise entrusts, transfers or dismembers the overall management service to a third party without authorization, and contracts it to a third party in the name of subcontracting. 7. Other violations of mandatory provisions of laws and administrative regulations.