11 Fixes For ‘Failed To Download File, The File Contents Differ’ In Minecraft

Account to our enthusiastic gaming community, Minecraft is the best and equally popular sandbox game, developed fully using the Java programming language. This virtually infinite and procedurally generated exploration video game has amassed 141 million players worldwide, and gamers enjoy it even now.

Minecraft Game World

But Minecraft gamers have reported a download error message titled “Failed to download file, the file contents differ from what was excepted”, that pops up while starting the Minecraft launcher. Proceed to the section below to find appropriate troubleshooting steps and more details regarding the error.

How to Fix “Failed to Download File, the File Contents Differ” Error?

To know more about the download error message, we need to analyze its contents closely. According to a comment on Reddit, the complete Minecraft error message (that came after running Minecraft on a new PC) conveys the following message:

“Failed to download file, the file contents differ from what was expected.

Name: jopt-simple-4.5.jar

URL: https://libraries.minecraft.net/net/sf/jopt-simple/jopt-simple/4.5/jopt-simple-4.5.jar

Filename on disk: jopt-simple-4.5.jar

Path: C:UserslucasAppDataRoaming.minecraftlibrariesnetsfjopt-simplejopt-simple4.5jopt-simple-4.5.jar

Exists: File

In simplified terms, the message above means that when the Minecraft launcher attempted to download game files (jar files), the file contents are different. This might occur due to the following reasons:

  • Incomplete or interrupted download of game files due to Antivirus software or Windows Firewall blocking the Internet connection
  • Error in the Minecraft launcher system files (Outdated Minecraft Launcher or Invalid files)
  • Presence of corrupt mods that messed with Minecraft launcher’s jar files
Failed to download file, the file contents differ from what was expected Minecraft error

Worry not, because our complete guide on fixing “Failed to download file, file contents differ from what was expected” includes proper troubleshooting steps to fix Minecraft launcher and negate any file loss. If one method fails to work for you, follow the corresponding solution.

Solutions To Fix Failed To Download File, The File Contents Differ From What Was Expected

  1. Shut Down and Restart
  2. Update Minecraft from the Minecraft Launcher
  3. Replace the .jar file with new ones
  4. Open Minecraft through the Vanilla Launcher
  5. Set Java to launch files with .jar extension
  6. Turn off the Antivirus Software
  7. Turn off the Windows Firewall
  8. Download the .jar file Using a VPN Connection
  9. Remove any previously-installed Corrupt Mod
  10. Download the File from Internet Manually and Place it in the Minecraft Directory
  11. Reinstall the Minecraft Launcher

Method 1: Shut Down and Restart

Before we get into troubleshooting steps that are advanced and require a considerable number of changes, it is always better to try something more straightforward and manageable. If you receive the Minecraft error (Failed to download file, the file contents differ from what was expected), it is better to restart the device, which could unexpectedly solve the download error.

  • Launch the start menu by clicking the Windows icon in the taskbar.
  • Open the Power menu by clicking on it, which contains the option to Shut Down, Restart, and put your computer to Sleep.
Shut Down and Restart
  • Click on Shut Down to turn your computer off. Start it again by pressing the power button on your PC or laptop.
  • After the computer boots up, relaunch the Minecraft client to see if the error has been fixed. Restarting your computer regularly can correct any error that occurs in the long run because it resets the services and deletes any temporary obstructing files.

Proceed to the next step if the repair process doesn’t work.

Method 2: Update Minecraft from the Minecraft Launcher

If you are receiving the Minecraft failed to download file, the file contents differ from what was expected error, the problem might not be on your side. Developers often make mistakes in the source code of games, for which downloading of jar files fails. In those moments of distress, the Support team pushes hotfix to resolve the error, due to which we need to check for updates inside the Minecraft launcher.

  • Open the Minecraft Launcher by double-clicking the Minecraft icon shortcut on the desktop.
  • You will receive a prompt to log into your Minecraft account by providing the username and password.
Update Minecraft from Minecraft Launcher
  • Next to the username, click on Options.
  • Click on the big Force Update button to recheck if there is a new update available for Minecraft.
  • The Minecraft Launcher will restart after installing the new game version if there is an update. Log in to your account to see if the download file issue is fixed.

Method 3: Download the File from Internet Manually and Place it in the Minecraft Directory

This solution works the best for both Windows and Mac computers. The essence behind this solution lies in the fact that if the Minecraft launcher fails to download new .jar files, you go the extra length and download it for the game itself and replace the installation files with the new ones. Follow the troubleshooting steps below:

  • Launch a notepad or any text editor on your computer. It will be needed later.
Launching the game failed Minecraft error copy URL Path
  • Fire up the Minecraft launcher by opening the game from the desktop. After launching, the download error pops up. A URL will be mentioned within the error message, as shown below. Copy the URL by selecting it and pressing Ctrl + C.
  • Head over the notepad (by pressing Alt + Tab) and paste the URL (Ctrl + V) there.
  • Move to the Minecraft Launcher error message and copy the Download directory mentioned under Path as shown below. Change to the Notepad window, and paste the Path in a separate line.
  • You may now close the Minecraft Launcher as we have copied the necessary info.
  • Open an Internet Browser of your choice, and inside the address bar, paste the URL from the Notepad. Press Enter to navigate to the download site.
  • You will receive a download prompt for the jar file. Accept it and let the downloading complete.
  • Open the Windows Explorer, and head over to the Downloads folder. Copy the .jar file you had just downloaded.
  • Open the Notepad, and copy the Path to Minecraft installation files.
  • Open another Windows Explorer window, and paste it into the navigation bar. Press Enter to navigate to Minecraft’s game files.
  • Copy the necessary jar files from the Download directory to the Minecraft folder. Click Overwrite all if you receive a prompt for replacing old files with the same name.
  • Restart your computer. Run the Minecraft Launcher, and you shouldn’t face any problem starting the game.

Method 4: Open Minecraft through the Vanilla Launcher

The Vanilla version of the Minecraft Launcher has been designed to enjoy Minecraft without any mods, i.e., it is the standard Minecraft. If the error occurs due to a glitch in a mod (after applying mod to the non-vanilla launcher), opening Minecraft through the vanilla launcher might solve the problem in gaming laptops.

Minecraft World
  • Exit the Non-Vanilla Minecraft Launcher window, and close it from the system tray.
  • Run the Minecraft native (Vanilla) launcher from the desktop and press Play.
  • Let the game run until you reach the Create Game Screen window. Close the launcher after that (from the system tray as well).
  • Open the Non-Vanilla Minecraft Launcher (the launcher you usually use), and check if the download issue has been fixed.
  • Twitch users may need to click on the Mod Pack and, at the launcher page, switch the game to Vanilla before opening it. Allow it to fully load, then shut it, then repeat for the Mod Pack to see whether the problem has been rectified.

Method 5: Set Java to launch files with .jar Extension

Minecraft is a Java-based game that uses Java application runtime files (or jar files) to help manage the inside game mechanics. Hence, Java (or JDK) is required to run files with jar extension type, else the jar files won’t be parsed correctly and cause incompatibility issues. Modifying the file opening preferences will solve the problem.

  • Open the Run Window by pressing the shortcut key (Win + R).
Launch jar files with Java JDK
  • Navigate to the following path name by typing it in the Run bar: %appdata%.minecraftassetsindexes
  • Inside the folder, right-click on a file with .jar or .java extension (If extensions are not displayed, you need to check Fine name extensions in View panel of Windows Explorer)
  • Click on Properties.
Select Java JDK to open jar files
  • Click on the Change button given with the Open With category, and select Java or OpenJDK Platform Binary application.
  • If you don’t see Java listed, download Java from the given link – Java JDK 17
  • After selecting, press Apply to confirm and choose OK to exit from the window.
  • Open your Minecraft Launcher again to see if the download starts. If you still receive the “failed to download file” error, proceed to the following method.

Method 6: Turn off the Antivirus Software

Minecraft consumes a lot of bandwidth to download updates and jar files when connected to the Internet. Such high consumption can lead to your Antivirus software flagging the Minecraft launcher as suspicious and blocking Minecraft’s connection with the Internet.

Follow these steps to see if turning off the Antivirus software fixes your Minecraft “Failed to download file, file contents differ from what was expected” error.

Note: for demonstration purposes, we use how to disable the Real-time protection inside Windows Defender since it is the default antivirus for most Windows 10 systems. The procedure is similar for different antiviruses.

  • To Launch Windows Defender, head over to the Start Menu (Win key) and press Settings (Gear icon).
Click Update & Security in Settings
  • Go to the Update & Security category, and pick Windows Security from the left pane.
Click on Manage Settings under Windows Security
  • Click on the link for Virus & Threat protection (on the right-hand space), and then Manage Settings.
Turn of Real-time protection in Windows Defender
  • Turn Real-time Protection off by clicking on its toggle button. The protection service has been temporarily stopped, and you can start the Minecraft launcher to see if the download issue has been fixed.

Method 7: Turn off the Windows Firewall

The Windows Firewall has been designed to fend off unauthorized users from accessing precious content you have on your Windows PC. But in some unexpected cases, the Windows firewall does more harm than good, and in this case, it might prevent Minecraft from accessing the jar file it wants to download. Follow up on the steps below to turn off the Windows Firewall:

  • Open the Control Panel by going to the start menu and typing Control Panel in the Search Bar.
  • Select the System and Security category from the list of icons.
  • From the listing on the right side, select Windows Defender Firewall (IF you do not find this setting, try to look for just Windows Firewall instead)
  • On the left side of the screen, select the option to Turn Windows Defender Firewall on or off.
Turn off Windows Defender Firewall
  • Select the bubble beside Turn off Windows Defender Firewall (not recommended).
  • If you are connected to a Public Network, select the same bubble in the second category as well.
  • Click on OK to confirm and save the changes.

Now that the firewall has been disabled try to launch the game and see if you managed to fix Minecraft.

Method 8: Download the .jAR file Using a VPN Connection

The problem overview of the download error in the Minecraft launcher states that the jar file (mentioned under the Filename on Disk category) could not be downloaded.

Since the reason is not clarified officially, a worthy assumption is that your home server has trouble connecting to the Minecraft servers, or there is a glitch in Minecraft’s regional servers. Connecting to a VPN might help in this case, and follow the steps to fix Minecraft:

Download MInecraft jar files using VPN connection
  • Download and install a free VPN application on your PC (if there isn’t any installed previously)
  • Close the Minecraft Launcher from the system tray.
  • Launch the VPN from the desktop by double-clicking on its icon.
  • If it is already running, connect to a server that is away from your country.
  • After the connection has been established, launch Minecraft again and check if the download issue has been resolved.

Method 9: Remove any previously-installed Corrupt Mod

If you manage to run Minecraft through the vanilla launcher but not from its original launcher, the download issue is probably caused due to a corrupt Minecraft mod.

You can attempt a directory repair through data recovery tools, but removing the mods is more straightforward and reliable. Follow the steps below to remove them:

  • Close the running Minecraft Launcher and exit from the system tray.
  • Open the Run window (Win key + R).
Open Minecraft appdata folder in Run
  • Type the following and press enter: %apdata%
  • Open the .Minecraft directory by clicking on it, and double-click the mods folder inside.
Delete corrupt mods inside mods folder Minecraft
  • Copy all the content present there, and paste it to a different location.
  • Delete everything inside the Mods folder. (Shift + Delete key)
  • Relaunch the Minecraft Launcher, and check if the download error is fixed.
  • If it is working, exit from the Launcher (as well as the system tray).
  • Copy one of the mods from the different location, and paste it into the original %appdata&/.minecraft/mods folder.
  • Open Minecraft and see if the error is occurring again.
  • In this way, copy the mods one by one to the mods folder, and run Minecraft to check and find the problematic mod. After you single out the problem, either update the mod or contact the mod developer to fix the issue.

Method 10: Reinstall the Minecraft Launcher

If none of the above methods worked for you and you landed in this final solution, be assured that going through these steps will definitely fix Minecraft. The “failed to download” issue might occur due to a corrupt installation of the Minecraft Launcher, and the only straightforward way to fix it is by reinstalling the game.

  • Firstly, we need to transfer the mods and Minecraft savegames to a safe location before we reinstall Minecraft.
  • Open the Run dialog box through the shortcut key (Win + R)
  • Type the following path for installation files inside the search bar: %appdata%
  • Open the .Minecraft directory, locate the Saves folder, copy it, and paste it into a secure location (If you want to resume playing Minecraft from where you left)
Transfer Minecraft Savegames to a safe location
  • Do the same for the Mods folder (only if you have gone through the previous method, and there is no error in the mods)
  • Open the Windows Start Menu and find Minecraft from the list of installed apps.
  • Search for it if you cannot find it there.
Uninstall Minecraft from Windows Start menu
  • Right-click on Minecraft and press Uninstall. Confirm your action by pressing Uninstall again and following the on-screen prompts to uninstall Minecraft
  • Reboot your PC, and go to the following folder by typing this in the Run window: %appdata%
  • Completely delete the .Minecraft folder.
Delete Minecraft frolder in these 3 folders
  • Open AppData by typing it in the Run window. Delete all Minecraft folders from the following 3 places: Local, LocalLow, Roaming.
  • Reinstall Minecraft by downloading the game from the official website, install it by following the on-screen prompts, and restoring the save and mods folder to its usual location.
  • After you reinstall Minecraft, the “Failed to download file, the file contents differ from what was expected” error will be fixed.


Why Are There Error Codes?

Error codes may be numeric or alphabetic and are used to identify the kind of mistake that occurred as well as what caused it. Codes for errors help troubleshoot by providing a concise description of what went wrong. The most typical application of this feature in consumer items is to help identify the specific fault with the product when anything goes wrong, such as when the Blue Screen of Death appears.

How Do I Fix Java Error 1618?

– End Other Installation Applications
– Restart your computer and reinstall
– Uninstall previous Java and reinstall

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