Many Airbus planes need a new computer update. The planes have a problem with sun rays. The sun rays can change the plane's computer numbers. This is not safe.
About 6,000 planes need this fix. Big airlines like Air France have these planes. The fix is like a new program for the computer. For most planes, it takes three hours.
Some old planes need a new computer. This takes more time. Some flights are late or canceled because of this. The plane companies say sorry for the problems. They say this fix is very important for safety. Now, most planes are flying again.