Plutonium

My Launcher crashes everytime when I hit the play button. I already try to install everything new and I also switched off my windows defender that maybe blocks a launcher data. I done every step that it listed in the guideline (download the English tool for MW3 at steam, download the DLCs and paste it in the MW3 folder + I also done the torrent step and everything run smooth. Can someone help me and explain why the launcher is still crashing?