Fans were turned away on game day because of safety concerns over their seating section, which included temporary seats.
In addition to the December revelation, more questions were raised during the construction in January, but the city says the issues were never fixed.
So on Super Bowl Sunday, inspectors declared the seats unsafe and over 400 angry fans were told their tickets would not be honored.
The city said the contractor who built the seats is to blame. The contractor said he has a safe track record, and that the city and the NFL are using him as a scapegoat.
The lawsuit, filed in Dallas, accuses the NFL, the Dallas Cowboys and team owner Jerry Jones of deceiving hundreds of fans. It alleges breach of contract, fraud and deceptive sales practices.
The Cowboys declined comment.
The Associated Press contributed to this story.