ZModeler3 Custom Liveries don't work

[FluffyPotato]

Hello ladies and gentlemen!

I've been working on a vehicle, created a UV for the Livery.
Created a template for it, and now it doesn't show that it load any liveries at all.

The tuning tool has the option grayed out.

What I did so far:

• Added FLAG_HAS_LIVERY to vehicles.meta
• Applied paint:3 to material vehicle_generic_smallspecmap [PAINT:1].
  That's how the vanilla vehicles work with liveries. I thought It might do the job.
  

Thank you in advance - I'm confused and don't know what else I should try.
Stay safe & healthy

Solved by a friend:
The DETAIL2 has to be set to the livery.dds, which somehow got reset.