If you're trying to play Minecraft and you encounter the error message "Internal Exception: java.lang.IndexOutOfBoundsException: readerIndex(142) + length(8) exceeds writerIndex(148): UnpooledByteBufAllocator$InstrumentedUnpooledUnsafeHeapByteBuf(ridx: 142, widx: 148, cap:148)", don't worry - there are several solutions you can try.
Solution 1: Clear Your Minecraft Cache
The first thing you should try is clearing your Minecraft cache. This can help resolve any corrupted files that might be causing the error.
- Open the Minecraft Launcher.
- Click on "Launch options" on the top right corner.
- Click on the profile that you're using to play Minecraft.
- Toggle on the switch for "JVM Arguments".
- Delete any existing arguments.
- Paste this in the text box:
-Dfml.ignorePatchDiscrepancies=true -Dfml.ignoreInvalidMinecraftCertificates=true
- Save your changes and launch the game.
- Try to reproduce the error.
If the error persists, proceed to the next solution.
Solution 2: Update Your Java Version
If your Java version is outdated, it can cause conflicts with Minecraft and result in errors such as this one.
- Go to the Java website and download the latest version of Java.
- Install the latest version of Java.
- Restart your computer.
- Launch Minecraft and see if the error still occurs.
If the error still occurs, proceed to the next solution.
Solution 3: Disable Your Firewall and Antivirus
Sometimes, your firewall or antivirus software might be blocking Minecraft from connecting to the server, which can cause the error.
- Temporarily disable your firewall and antivirus software.
- Launch Minecraft and try to reproduce the error.
- If the error doesn't occur, you'll need to add Minecraft as an exception in your firewall and antivirus software.
- Enable your firewall and antivirus software again.
If the error still occurs, proceed to the next solution.
Solution 4: Reinstall The Modpack
If none of the above solutions worked, you can try reinstalling The Modpack altogether.
- Backup your Minecraft worlds, if necessary.
- Deleted the modpack from the launcher.
- Reinstall The Modpack.
- Launch Modpack and see if the error still occurs.
If the error still occurs, it's possible that there's a problem with the server you're trying to connect to. Try connecting to a different server to see if the error occurs again. If it does, contact Minecraft support for further assistance.