Texture fallbacks for both cargo pallet and loader.
That doesn't say much, to know what you did wrong, I should see what your folders are, where your textures are, etc.
ALSO: Every few service request couatl crashes (press ctrl+f12 and select deboarding-crashes after loading vehicles)
Most likely because you made some error in the sim.cfg, not possible to check without looking at it.
Something that is surely wrong is:
Loader
fallback.3=..\..\FSDT_Staircase_USER\texture.PR
Pallet
fallback.1=..\..\FSDT_Staircase\texture.PR
So, where is your texture file ? If you followed the Paintkit advice, you should have it into ..\..\FSDT_Staircase_USER\texture.PR as in the Loader, but then the path in the Pallet is wrong.