Boeing, the US aircraft maker, has announced that it has discovered a new 737 MAX programming problem that could hinder efforts to renew the plane's license.
The new problem relates to a program that is supposed to ensure proper operation of certain screens in the twin-engine plane.
A Boeing spokesperson said, in one of the tests, that one of the screens did not work due to the program on launch.
"We are making necessary updates and working with the Federal Aviation Administration to deliver the change and inform our customers and suppliers," the spokesman added.
"Our top priority is to ensure the safety of (737 MAX) and to comply with all regulatory requirements before returning to service," he added.
A spokesman for the Federal Aviation Administration said the administration was "pursuing a comprehensive process to return the Boeing 737 MAX to passenger service."