Frustratingly, Minecraft’s “Failed to download file, the contents differ from what was intended” issue can occur. When this occurs, you will be unable to spend hours mining in your virtual environment or exploring the dungeons you had intended to visit.

If your Minecraft launcher is having trouble downloading the file as well, we’ll go over several potential solutions to assist you repair the problem.


1: Take Note of the Message Given in the Error Message

Before trying to add any more fixes, you may want to see if the Minecraft launcher is getting what it needs. The launcher has encountered an unexpected condition, as shown by the pop-up box, and the problem may be remedied by downloading the needed file and manually adding it to the installation directory.

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

The helpful part is that the error message tells you exactly where on your computer to put the file when you download it from the given URL.

You should save the error message in a separate file so that you can easily reference the path information while downloading and replacing the file. So, after that, do what I say:

  1. Just paste the link into your browser of choice to start the download immediately after you copy it.

2. Go to the location in File Explorer that was given in the error message and paste the          downloaded file there.


3. When replacing the jopt-simple-4.5.jar file, make sure to delete the original before              pasting the new one.

Upon changing the file, restart the launcher to ensure that the error has been fixed. If not, unzip the downloaded file in the same folder you pasted it in previously. If the problem remains, let the copied file be placed in the directory and perform the below remedies.

Method 2: Change the Opening Preference of Files With the .JAR Extension

A Java runtime environment is required to open .JAR files. You need to set the right file opening preference for Java to execute all classes and resources of a .JAR file in one request.

The files won’t be executed if any other application is configured as default to open these files. This erroneous execution can likewise be accountable for the error under consideration.

To update it, take these steps:

  1. Go to C: > Users > %username% > AppData > Roaming
  2. Navigate to .minecraft.
  3. Right-click any file with the .JAR extension and select Properties. (In this scenario, we’re modifying the file opening option using a .JAR file in the addons folder).
  4. Right next to Opens With, click on the Change button.
  5. Select the Java (or JDK) to open such file extensions.

If you like, you may repeat the same process for any additional file with the .JAR extension to adjust the file opening preferences. However, you can skip this step if the file extension is already configured to open in your desired file opening choice.

Method 3: Rule Out Corrupted Mod Issues

If you’re a power Minecraft player who doesn’t hesitate to check out every new Minecraft mod you come across, a corrupt mod file might also lead to this issue. To rule this out, perform these simple steps:

  1. Navigate to the following path:


2. Get a copy of the modifications folder and move it.

3. Get rid of the game’s original mods folder.

4. Start Minecraft all over again.

If fixing the issue involves deleting the modifications folder, then one of the mods is broken. Remove the recent add-on first, please. To check if the issue has been fixed, re-start the launcher and try again.

When an issue remains, it’s because the corrupted mod is still present in the game’s files. To determine which mod is causing the problem, try erasing it one by one from the mods folder and restarting the launcher each time. It’s over after the offending add-on has been filtered out and removed.

If removing all add-ons doesn’t help, try the other solutions listed below.

Method 4: Issues With The Launcher Should be Ruled Out

The launcher itself is likely to be the source of the problem if you primarily use a non-vanilla launcher with mods. Find the directory that contains the non-vanilla launcher’s installation files and remove them. Then, activate the vanilla booster.

If starting up using the “vanilla” launcher cures the problem, you should never go back to using anything else.

Method 5: In Microsoft Defender’s Firewall, Whitelist The Minecraft Launcher.

The firewall in Microsoft Defender could be preventing the launcher from downloading the data properly, leading to the problem. There is a good likelihood that the problem can be fixed by whitelisting Minecraft in the Firewall settings (letting the programme via the Firewall).

To do so, go as described below:

  1. To access the Windows configuration menu, right-click the Start button.
  2. Enter Update & Security.
  3. Select Windows Security from the menu bar’s left-hand side.
  4. Use the menu on the right to access Firewall & network protection.
  5. In the right-hand pane, select Allow an app past the firewall.
  6. To enable the Allow another app… option, first select Change settings.
  7. To access the Minecraft launcher, select the Browse button.
  8. Follow this by selecting the Plus sign.
  9. Mark the “Private” and “Public” checkboxes, respectively.
  10. Hit OK.

Microsoft Defender Firewall can be temporarily disabled, if desired. If the file still doesn’t download, try starting the launcher again. If the problem remains after that, you should reinstall Minecraft.