Step 1: Plane is returned from lease and placed in storage.
Step 2: Seat config of plane is changed while in storage.
Step 3: While in the process of reconfiguration, the plane is taken out of storage.
The "Extra Maintenance"-time is correctly changed to 3+5 days, but some of the engineers use salt water to clean the aluminum-airframe; after they are finished taking the plane out of storage... 10% condition

Just recreated today in GW2:
https://www.airwaysim.com/game/Aircraft/My/View/63618/Please dont forget to adapt my two 757s that are in non-flying condition. And also I think that payback of two months worth of insurance premiums (~20M) is adequate to compensate for the grounding of the planes due to this bug (accounting for leasing costs, maintenance and other associated issues).
p.s.: it is a also a bit weird, that if you put a plane into a Ccheck, it can get out of that check in a non-flying-condition
