I am trying to give my Marine a Combat shield when he becomes level 2 veterancy. Currently I have tried changing the 'use shieldwall' requirements to counting my veterancy behavior, but its not working. Do anyone of you guys have any ideas how i can accomplish this?

It's tricky to enable an upgrade for a unit through veterancy since upgrades apply to all units.

Your best bet would be to recreate the Combat Shield as a behaviour (Buff). Simply make it a buff that lasts forever, increases hitpoints by 10. You will need to modify the Combat Shield actor/model by creating a new actor of type ModelStyleContinuous (or something, don't have the editor open at the moment), so that this new actor has the 'birth' event triggered when the buff is applied to the marine. Then you simply add the buff to the unit once veterancy hits level 2.

If you need more help with this, just let me know and I'll fire open the editor.

Sorry, I dont really get it. XD

Okay I'll spoon feed you.

*making video to upload now - will edit post in about 20 minutes*

Thank you.

Edit: I've got it working but I need to go make dinner now. Will post the solution soon.

Text version so long:
Create your veterancy behaviour (veterancy).
Create a Veterancy Combat Shield behaviour (buff) that modifies your units hitpoints and maybe armor.
Set your veterancy behaviour to enable the veterancy combat shield behaviour at your desired level.
Give both behaviours to your unit (marine I presume).
Add a validator to the Combat Shield behaviour that removes the behaviour unless the veterancy is at the desired level.
Create a trigger that fires when a unit gains a level.
Conditions check triggering behaviour == Veterancy Behaviour
Also check experience level of triggering unit (to your desired level)
Actions: send actor message to triggering unit "AnimClear Cover".

Basically, Marines use the shield as part of their base model file but it is hidden through an animation sequence called 'Cover'. When the upgrade is researched, the units are told to stop using the 'cover' animation, and then the shield appears.

Ok i got it thanks.