If you can’t install Minecraft Forge because of the invalid or corrupt jarfile error, keep on reading this guide to learn what might have caused it and how you can fix it.
How to Fix Invalid or Corrupt Jarfile in Minecraft Forge
1. Make sure the download is complete
If you’re trying to launch the game before the download is complete, you’ll get all sorts of errors, including the invalid or corrupt jarfile error.
Make sure Minecraft Forge is showing up in your downloads folder. Then, check if your browser is not blocking it for some reason.
Go to your browser’s download manager, recover the file and try again.
2. Use a different browser
Many of the users who complained about invalid or corrupt jarfile errors in Minecraft used Firefox to download the game.
It seems that Firefox often blocks the Minecraft Forge download. That’s why we suggest you should try to download the game using a different browser.
3. Update your Java version
Ensure you’re running the latest Java version on your computer. Download a newer version if you’re running an outdated version.
4. Close background programs
When downloading Minecraft Forge, or any other game or program on your computer, remember to close all the programs and processes running in the background.
Some of the programs actively running on your machine might block the download process. Or they may interfere with Minecraft Forge when you try to load the launcher.
You can close background programs using the Task Manager or by clean booting your computer.
If you prefer to use the Task Manager, select the Processes tab and right-click on the programs you want to disable. Then select End Task.
You can also temporarily disable your antivirus and firewall. These programs might mistakenly flag certain Minecraft files as suspicious and block them.
Don’t forget to re-enable your antivirus and firewall after you downloaded and installed Minecraft Forge.
We hope something helps.