UE Crashes building

Hello guys, I’ve been usign UE 4.8 (it updated to 4.8.1 a week ago) but today he decided to not build my projects. When the swarm goes to 100% and it begins to build UE crashes. Sometimes UE crashes when get 33% building, sometimes UE crashes immediately when the build begins (after Swarm gets 100% and end his process). idk what is happening, yesterday UE was working perfectly, but today my epic Launcher updated and this problem came to me.
Someone help me please!