(https://i.imgur.com/hu5SZSf.png)
i also tried deleting all air_evt and related air_ files from the grf and redoing the map generation, the result was essentially the same, no error but the ingame map returns all unwalkable cells(can't click anywhere to move even if it's actually movable there ingame)
this is the only file with any issue, i don't mind if the airship maps don't receive flat cells treatment, or do, i just want to be able to move(afaik it's just the part where you exit terminal and are heading towards the airship itself, not anywhere else)