Boeing has reportedly discovered an additional software problem in their 737 Max planes that regulators have deemed critical to flight safety, The Washington Post reports. The problem, which the company described as “relatively minor,” was reportedly found when the company was conducting a review of the stall-prevention system—which is thought to have caused the two fatal airplane crashes in Indonesia and Ethiopia. Two sources told the Post that the Federal Aviation Administration still considers the latest issue important to flight safety and has ordered the company to fix the issue before the aircraft can fly again. The company reportedly said it expected to have a solution to the issue “in the coming weeks.” A total of 346 people died in the two separate crashes that have been linked to the plane’s MCAS system, which is believed to have erroneously sent the aircraft into a nosedive shortly after takeoff due to faulty sensors.