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.

Here's what you should know about the differences in Minecraft Java and Bedrock for Windows before you choose which to install.

To fix Internal Exception: java.io.IOException, An existing connection was forcibly closed by the remote host Minecraft error, you need to follow the given solutions.