Everytime i try to build the lights and the level, UE crashes

Assertion failed: RelevantLights [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Engine/Private/ModelLight.cpp] [Line: 976,

please help, i’m in a crysis

Solved: Basically if you encounter this error too, check the map log and it will tell you that there’s a BSP material which is useless, this is caused by a material you placed in the editor that has a resolution way too big for your pc to handle and will drain the ram of the editor and close it… while compiling… For solving this: simply delete the brush with the material that has a big render