I recently had an issue, involving extreme lag on 1.9. I was told that there was an issue with my graphics drivers, and how to fix it. I attempted to fix the drivers, and once I launched it Minecraft had worked normally again. After that though; it became laggy again. It continued to crash after trying to launch a world/server also. I am unsure if I have not fixed the driver issue properly, and I need some extra guidance with fixing the issue with my drivers. The previous issue is here https://bugs.mojang.com/browse/MC-100094