Hello CUP team, please investigate your class tank_f inheritance.

Loading CUP Vehicles and its required dependencies removes parameters from class "tank_f" >> "sounds" >> "engine". Likely some class forward-reference without proper load-order does this by accident.

The .rpt is sadly a bit unhelpful:

Updating base class Sounds->, by CUP\TrackedVehicles\CUP_TrackedVehicles_T34\config.bin/CfgVehicles/Tank_F/Sounds/ (original CUP\TrackedVehicles\CUP_TrackedVehicles_T34\config.bin)

It is not specific to the T-34. That T-34 addon simply happens to be the first in the load-order that touches on Tank_F after some other addon accidentally changed its parent. I wasn't able to locate which addon within CUP does this.

The config path "CfgVehicles" >> "Tank_F" >> "Sounds" >> "Engine" is a completely empty class when starting Arma 3 like this:

"-mod=G:\Steam\steamapps\common\Arma 3\!Workshop\@CBA_A3;G:\Steam\steamapps\common\Arma 3\!Workshop\@CUP Weapons;G:\Steam\steamapps\common\Arma 3\!Workshop\@CUP Units;G:\Steam\steamapps\common\Arma 3\!Workshop\@CUP Vehicles"

Starting without any mods keeps that class's content intact. Starting with just @CBA_A3 also keeps that class in tact.

I guess that either the load-order causes an empty class to be created instead of just being referenced, or it could even be that it was referenced incorrectly as class engine{}; instead of class engine;