I have two different problems that are most likely related:
1 - Null Pointer Exception on Multiplayer
I've been playing Minecraft for around 3.5 years now, but this is the first time I've experienced this error (I've dealt with and solved numerous others). For MC 1.11.2 and below (unmodded), multiplayer works perfectly fine. However, MC 1.12 and MC 1.11.2 Optifine multiplayer does not work. The same error occurs for every server I try to join. The error is as follows:
15:32:56 bkp Connecting to mc.hypixel.net., 25565
15:32:56 bkp Couldn't connect to server
java.lang.NullPointerException: group
at io.netty.bootstrap.AbstractBootstrap.group(AbstractBootstrap.java:84)
at gw.a(SourceFile:276)
at bkp$1.run(SourceFile:59)
I have: uninstalled all outdated Java versions, updated Java, allowed all Java processes in Windows Firewall, reset the ".minecraft" file, reset network adapter twice, logged out and logged into Minecraft multiple times, done some stupid internet rituals that include trying over and over and joining servers slower, uninstalled McAfee and Avast! (they had already been uninstalled, I checked), and restarted my computer after each of these methods. Nothing is working, and since 1.12 came out, I can't join any 1.12 servers. Are there any methods I may have missed? I have F-Secure Safe and Qustodio, neither of which SEEM to be causing any problems.
2 - Singleplayer crash when loading world
Minecraft single player does not work either, not in MC 1.11.2 or in MC 1.12 (I have not tested other versions). I can create or join a world, the game output shows no errors, the world loads to about 97%, then the game freezes and eventually crashes. This may be related to problem #1, but it is not as urgent, as I typically play on multiplayer anyways.
I have searched and troubleshooted from results on Google for around a total of 8 hours for two days, but nobody seems to have my exact problem. I need help.