For a while after 1.12.2 I couldn't open Minecraft at all, the launcher would launch the game and the exe would come up but it would never move past the Mojang screen and when I closed it the launcher would notify me of a crash. After a couple tries the exe stopped popping up completely. After doing some googling several times I couldn't find anything on the issue that was current but I uninstalled both Minecraft and Java and reinstalled them and then I updated my graphics driver and still had the same issue. After messing with it a bit more I opened my task manager and saw that when I launched Minecraft, several more launchers would open themselves. (attachment 1;bug1.png) I closed the launchers and the exe would pop up and say Not Responding for about 1 to 2 minutes. (attachment 2;bug2.png) And then finally the game would be playable. (attachment 3;bug3.png)