We need more information, for example which scene from which creator is it? (Edit: found it, Hunting a wild succubus by Ispinox) Is the scene lighting correct after loading the scene? Do you have this problem only in this scene and the rest is working fine? Are scenes from the same creator working?
I would debug the scene to get more information. Check the lights in the scene, are they off when everything turns black? Can you add a new light and will it work? What are the global lighting settings? As the scene is using the timeline plugin, are there triggers to control the lights?
If the scene is complex and you can't seem to find anything, you could also check the scene json file and search for lights or "trigger" for example. A simple example, where a light is turned off, another one's intensity set to 0 and the third entry setting the Global master lighting to zero through triggers called in the timeline plugin:
"Triggers" : [
{
"displayName" : "Licht links blau aus",
"startActions" : [
{
"name" : "Licht links blau aus",
"receiverAtom" : "Light Left Blue",
"receiver" : "Light",
"receiverTargetName" : "on",
"boolValue" : "false"
},
{
"name" : "Licht front aus",
"receiverAtom" : "Light Frontspot",
"receiver" : "Light",
"receiverTargetName" : "intensity",
"floatValue" : "0"
},
{
"name" : "A_masterIntensity:0.00",
"receiverAtom" : "CoreControl",
"receiver" : "GlobalLighting",
"receiverTargetName" : "masterIntensity",
"floatValue" : "0"
}