Decals showing as green square in game after cook

[Chromarz]

New to UE and this is my first real project. Ive been building a level now for the past month and ive been building, cooking & testing along the way. The decals were working at one point but now all of them show up as green squares like in the picture.

But when in the viewport in engine they show up fine. Ive even put a big stationary light just above the big test decal i was using as some people were saying on other posts that it could be lighting related.

Are there any other settings that could effect this? Has anyone seen this before? Am i being stupid?

[EliasWick]

The green texture you are referring to is the default unreal engine texture. The reason for why it has appeared, is most likely because the decal you have applied didn’t cook properly. Make sure it is included and is packaged in the final build to avoid this error.