Static lights black after build

Well, like always happens after I post something here, I figured out the issue a few minutes later.

The ambient occlusion of my material was bad configured and it became 100% black. I still not sure why it only affects the static lighting, but it also explains why, in other situations, my scenes always became a bit more darker after the light build.

I have this static mesh that represents a cave. It works fine with stationary lights. It also appears ok while in “preview mode” with static lights, like the imave below:

However, after build the lights (using a static light), the light disapears completelly:

The lightmap seems ok to me:

Both light and mesh are configured with static mobility:



I saw a lot of similar issues around the internet, but was not able to find an answer. I have no idea what is going on and how to fix it. Any help will be appreciated.

(ps: my gosh, what is going on with AnswerHub? It was a real pain to be able to post this question, lot of bugs, failed attempts etc. Almost drove me crazy here…)