Disaster starts after world migration

In /Steam/steamapps/common/Eco/Eco_Data/Server/Configs/Difficulty.eco check "MeteorImpactInDays" and make sure it is set to a value that is beyond the age of the world.

You can restore a backup of the save in the Storage/Backups folder, just copy the .db and .eco file of the last backup folder with your savegames name to the Storage folder and override it.

That was changed in Update 11.0, if you check the Disasters.eco.template you can see that setting does no longer exist in that config.

You need to load a backup before the meteor hit, otherwise the impact time setting has no effect. You also can't turn off the meteor when it already is on the map, it only decides on if one is generated, but doesn't remove an existing one.