Instructions to fix cinematics: go to "owned games" on gog galaxy, right click on Grim Dawn, hover cursor over "manage installation" and click "show folder". The game folder will pop up. In the game folder, click on the "video" folder. In the video folder, right click on the "Intro.ogg" file and click "properties". Change "Opens with:" to Media Player or VLC Media Player. Click apply and OK. The cinematic should work.