The Internal Exception Java.IO.IOException error usually occurs when you launch Minecraft, or when the game is underway. This error can be caused by a number of different things.

Reinstalled Minecraft and Java thrice. Restarted my router and played around with the firewall (my router is AT&T btw if that helps). Tried installing Netty, but, every time I do it breaks chrome.

java.lang.NullPointerException: Cannot invoke "io.github.apace100.apoli.power.Power.fromTag (net.minecraft.class_2520)" because "power" is null #171 ...

The “io.netty.channel.abstractchannel$annotatedconnectexception: Connection refused: no further information” error is a common frustration experienced by Minecraft players. This error message ...