A player cannot climb ladders on any of the FuelTank_01 structures due to an incorrect settings in ActionsManagerComponent.
The prefab in question is: ArmaReforger:Prefabs/Structures/Industrial/Containers/FuelTanks/FuelTank_01_green.et and any other variants.
The incorrect setting is the Omnidirectional flag - it should be switched ON on the bottom and switched OFF at the top.

In it's current state, the user is unable to see the Climb Ladder action, only from the 85 degree angle, which is next to impossible.

Example on Everon can be found in the middle of military base just south of Levie.