However, users have reported the jna-4.4.0.jar error. It’s an error code that pops up upon opening the Minecraft launcher. In this guide, we’ll show you what the jna-4.4.0.jar error is on Minecraft and how to fix it. Read this article to learn more.
What is the jna-4.4.0.jar Error?
As with other launcher errors, you’ll see the error message and some important information that you can use later to have an idea of solving this issue. Some users pointed out that it’s a software-related or a mod-related problem. Here’s what you can see in the error window:
1 What is the jna-4.4.0.jar Error?2 How to Fix the “Failed to Download the File, the File Contents Differ From What Was Expected” Error2.1 Fix #1: Check the URL on the Error Message2.2 Fix #2: Delete Corrupted Mods2.3 Fix #3: Exempt Minecraft from Windows Firewall2.4 Fix #4: Launch Minecraft via the Vanilla Launcher2.5 Fix #5: Set the Java Platform as a Default File Opening Preference2.6 Fix #6: Reinstall Minecraft3 Final Thoughts
“Failed to download file, the file contents differ from what was expected. Name: jna-4.4.0.jar URL: https://libraries.minecraft.net/net/java/dev/jna/jna/4.4.0/jna-4.4.0.jar Filename on disk: jna-4.4.0.jar Path: C:\Users[owner account name]\Minecraft\Install\libraries\net\java\dev\jna-4.4.0.jar Exists: File” In other words, the Minecraft launcher attempted to download game files (.jar files) and it found out that the game files are different or incompatible. This issue can show up on your computer due to several reasons:
Incomplete Download of Game Files – Whether due to a bad internet connection or a built-in antivirus, it’s hard to download game files in these situations. Most of the time, you’ll lack certain files, which is hard to know at first but can cause the jna-4.4.0.jar Minecraft error.
Corrupt or Faulty Mods – Some Minecraft mods on the internet can be outdated, corrupted, or faulty, depending on your source. Faulty mods can break the game which forces you to reinstall everything.
Outdated Minecraft Launcher – The Minecraft launcher is an app that’s free and is regularly updated. However, there are cases where users forget to download the latest version of this app which can lead to the jna-4.4.0.jar issue.
How to Fix the “Failed to Download the File, the File Contents Differ From What Was Expected” Error
Before going straight to the fixes, you can first try to restart your computer and see if the problem is still there. Another quick fix is to update Minecraft using the Minecraft launcher. This way, you can install all patches that can fix the jna–4.4.0.jar error. To update Minecraft from the Minecraft launcher, follow these steps: If it still shows up despite updating the Minecraft launcher, proceed to these fixes below. Make sure to go over them individually to see which one works best.
Fix #1: Check the URL on the Error Message
As mentioned earlier, the error message will display some critical information to help you solve this Minecraft launcher error. The URL that’s included in the message will let you download the file and replace it in the file path shown. To download the file and replace it via the indicated URL and file path, proceed to the steps below: Once this method doesn’t work, you can unzip the file in a similar folder. Then, you can check later on if you still see an error message.
Fix #2: Delete Corrupted Mods
Once you’ve been using a variety of mods for Minecraft, there’s a high chance that you’ll encounter faulty or corrupted versions. Although it gives you a personalized look at your game, you cannot appreciate it that much if the game cannot be opened. Deleting faulty mods can easily fix this issue. To delete defective mods on Minecraft, follow these steps: Corrupted Mods can also cause the dreaded “Minecraft LAN Not Working” error, so it is always good to regularly update them.
Fix #3: Exempt Minecraft from Windows Firewall
Many users are experiencing problems downloading critical game updates from the internet, especially when the Windows Firewall is in the way. Besides that, the firewall can also block important processes and can lead to the jna-4.4.0.jar error. To exempt or whitelist Minecraft from Windows Firewall, do the following:
Fix #4: Launch Minecraft via the Vanilla Launcher
If you want to play the standard version of Minecraft, you can use the Vanilla launcher as a temporary solution. Once you can open Minecraft using this tool, the problem might be related to the mods installed. To launch Minecraft via the Vanilla Launcher, follow these steps:
Fix #5: Set the Java Platform as a Default File Opening Preference
To open .jar files, you’ll need to use the Java runtime environment. However, sometimes it’s not set by default on some Windows computers. You can try selecting the file opening preference manually and check if this solves the Minecraft launcher issue. To set the file opening preference to Java, follow the steps below:
Fix #6: Reinstall Minecraft
As your last resort, reinstalling Minecraft will download all original game files that might have been overwritten or corrupted during a mod install. It gives the game a fresh start and will solve most Minecraft errors. Important: Since you’ll be reinstalling Minecraft, your game progress might be deleted, along with the current game files. You can manage to copy the Save folder first to avoid losing game progress while deleting all existing game files. To reinstall Minecraft on your computer, follow these steps:
Final Thoughts
Some users have experienced the “Failed to download file, the file contents differ from what was expected” error when playing Minecraft on PC. This error prevents you from playing the game unless the indicated game file is replaced with a new version. Hence, this guide can help you solve the jna-4.4.0.jar in the Minecraft launcher using easy-to-follow fixes.
