What happenes:

When I start the launcher, everything seems to be fine and everything works properly. When I start the game everything is fine too but when I try creating a new world / opening an existing world / entering a server the game would freeze on a 'Loading Terrain' screen and eventually crash. The game will also randomly crash if I try changing some settings and resource packs and after the game crashes or after I close the game the launcher crashes as well. If the launcher doesn't crash it doesn't give me any details about the game crash. There are no crash report files in the 'crash-reports' folder in my '.minecraft' folder for some reason so I cannot send any details about the crashes. (This issue can be fixed by using the old launcher, but I'm wondering if there's a way to fix this on the new launcher.)