Validity of MOU if it does not conclude in a Development Agreement

We signed an MOU with a redeveloper for our old apartment building of 6 members on May 11, 2022. However the MOU did not materialise into a Development Agreement ever. One of the members had a outstanding housing loan and he was unable to repay the same therefore it was not possible to go ahead with the redevelopment. The redeveloper as well as the society members tried to offer solutions to this one member however he refused to accept any of these. This same member has caused cancellations of other MOUs under various reasons in the last 6 to 8 years and the 30plus year old property remained undeveloped. Frustrated with these developments I sold my apartment to a buyer on September 07, 2023 (more than a year later post the MOU) with full disclosure of the above situation. The members in 2024 decided to go ahead with the redevelopment with the new buyer (he is also a developer) and the original developer has objected to this. I being the original member am served a notice for not seeking his NOC while selling the apartment. Please advice